Note: Descriptions are shown in the official language in which they were submitted.
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A SECURITY SHEET OR DOCUMENT HAVING
ONE OR MORE ENHANCED WATERMARKS
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. Patent
Application Serial
No. 12/997,390, filed February 23, 2011, and claims benefit of and priority to
U.S. Provisional Patent Application No. 61/911,141, filed on December 3, 2013,
U.S. Provisional Patent Application No. 61/911,831, filed on December 4, 2013,
U.S. Provisional Patent Application No. 61/911,885, filed on December 4, 2013,
and
U.S. Provisional Patent Application No. 61/924,000, filed on January 6, 2014,
each of
which is incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The invention generally relates to a security sheet or document
having
one or more enhanced watermarks.
BACKGROUND AND SUMMARY OF THE INVENTION
[0003] Security papers are used for manufacturing security documents
such as
banknotes, passports, postage stamps and the like. Conventionally, a wide
variety of
security features are incorporated into such security papers or provided on
their surface.
Known examples of such security features include watermarks, embedded and
windowed security threads, fluorescent pigments and the like.
[0004] Watermarks, which are recognizable images or patterns in paper
that
appear as various shades of lightness/darkness when viewed by transmitted
light or by
reflected light atop a dark background, have provided protection against
counterfeiting
security documents for hundreds of years. In fact, watermarks and their
engaging
designs are the most readily recognized security feature available to the
general public
for the authentication of security documents such as banknotes.
[0005] There is, however, an ongoing need to improve the security or
counterfeit
resistance of watermarked security documents.
[0006] The present invention addresses this need by providing enhanced
and
thus more counterfeit-resistant watermarks in paper and paper-like materials.
Specifically, the present invention provides a security sheet or document
having one or
more enhanced watermarks, the sheet or document comprising:
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a fibrous sheet material including one or more watermarks, wherein each
watermark has one or more first regions with reduced fiber densities relative
to
surrounding regions of the fibrous sheet material and one or more second
regions with similar or increased fiber densities relative to surrounding
regions of
the sheet material, and wherein each watermark has an upper or face portion
and a lower or back portion; and
means for enhancing the one or more watermarks by rendering them
visually enhanced, machine detectable/readable, or both, said means selected
from the group of:
a) one or more film-like or foil-like security elements at least partially
covering the face or the back portion of the one or more watermarks,
wherein the one or more film-like or foil-like security elements is in the
form of a band, strip, stripe, thread, or patch;
b) one or more non-film-like, non-foil-like security elements contained on
or within either or both the one or more first regions and the one or
more second regions of the one or more watermarks, the one or more
security elements selected from the group of:
i. recognizable or discernible indicia; and
ii. one or more substances that are color-imparting and/or
machine detectable or machine readable including, but not
limited to, ultraviolet (UV) or infrared (IR) reactive, luminescent
(i.e., fluorescent or phosphorescent), thermochromic,
photochromic, electrochromic, metal, or magnetic security
fibers, taggants, planchettes, dyes, pigments;
c) one or more polymer or resinous materials contained within the one or
more first regions and optionally the one or more second regions of
the one or more watermarks, the one or more polymer or resinous
materials having an index of refraction or combined (final) index of
refraction substantially similar to that of cellulose;
d) an optionally windowed second paper layer covering either the face or
the back portion of the one or more watermarks; and/or
e) one or more transparent or translucent areas surrounding each of the
one or more watermarks.
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[0007] In a first exemplary embodiment, the inventive security sheet or
document
is a single- or multi-ply paper that comprises:
a first paper layer including one or more watermarks, each surface of the
paper layer displaying either the upper or face portion of the watermark(s) or
the
lower or back portion thereof;
one or more film-like or foil-like security elements that at least partially
cover the upper or face portion or the lower or back portion of the one or
more
watermarks; and optionally
a second paper layer having a reduced basis weight compared to the first
paper layer and optionally one or more through windows, the second paper layer
covering either the upper or face portion or the lower or back portion of the
one
or more watermarks.
[0008] The film-like or foil-like security element preferably has a
color different
from the watermark(s) and the surrounding paper thereby enhancing the
appearance of
the underlying or overlying watermark(s) as well as enhancing the contrast
between the
underlying or overlying watermark(s) and the surrounding paper.
[0009] In one such embodiment, the film-like or foil-like security
element(s) is a
micro-optic security device that projects one or more synthetic images such as
the
MOTIONTm micro-optic security device, which is described in, for example, U.S.
Patent
No. 7,333,268. Such devices display colored images on a transparent or tinted
background and thus are well suited for use in combination with underlying
printed
information. It has been observed that these security devices appear to
provide the
watermark(s) with a multi-tonal appearance. As will be readily appreciated by
those
skilled in the art, multi-tonal watermarks present an even greater challenge
to a
counterfeiter.
[0010] In a preferred embodiment, the micro-optic security device is in
the form
of a surface-applied patch that covers all or part (e.g., one-half) of a
watermark, the
watermark containing one or more polymer or resinous materials within the
first and/or
second regions of the watermark, the one or more polymer or resinous materials
having
an index of refraction or combined (final) index of refraction substantially
similar to that of
cellulose. In one such embodiment, the region(s) also contains one or more
features
selected from the group of increased fiber density areas in the form of
recognizable or
discernible indicia, one or more substances that are color-imparting, and one
or more
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so-called second level security features that are machine detectable or
machine
readable (e.g., UV or IR reactive, luminescent, thermochromic, photochromic,
electrochromic, metal, or magnetic security fibers, taggants, planchettes,
dyes,
pigments).
[0011] As
will be readily appreciated by those skilled in the art, the micro-optic
security device may also be in the form of a surface-applied elongate security
band,
strip, stripe, or thread, or a partially embedded elongate security band,
strip, stripe, or
thread that is present in window regions of a second paper layer (i.e.,
windowed thread).
[0012]
Micro-optic devices such as the MOTIONTm device may be designed such
that when registered with the watermark(s), synthetic images projected thereby
are
combined with the watermark design(s). For
example, in the above-referenced
embodiment, the synthetic image(s) generated by each patch may coordinate or
link in
with the watermark design(s). The synthetic image(s) may also complete the
watermark
design(s) or locate within the design(s). As will be explained in more detail
below, this
may be a one-sided or two-sided feature.
[0013] In
another such embodiment, the micro-optic security device(s), which is
also described in, for example, U.S. Patent No. 7,333,268, displays colored
images (of
any color, including white and black) on a translucent or substantially opaque
background of a different color. In this embodiment, the micro-optic security
device(s) at
least partially covers and visually camouflages either the upper or face
portion of the one
or more watermarks, or the lower or back portion of the one or more
watermarks. The
watermark(s) is not visually discernible in reflected light from the covered
side of the
paper layer, but is visually evident in reflected light from the uncovered
side of the paper
layer, and in transmitted light from both sides of the paper layer.
[0014] An
inherent benefit in the exemplary embodiments of the present
invention which employ a partially or fully overlying or underlying film-like
or foil-like
security element such as the MOTIONTm security device is the increased
durability of
each watermark. As is well known to those skilled in the art, one of the
primary
requirements of banknotes and other secure documents is that the document and
its
security features must resist the effects of circulation. These
documents/features must
be durable (i.e., resistant to fold damage, tearing and soiling) and resistant
to moisture
and chemical absorption. Covering all or part of the watermark(s) with an
applied film,
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foil, band, strip, stripe, thread, or patch serves to physically protect the
watermark(s)
from damage during circulation and handling, thus increasing its durability.
[0015] Due to the increased durability afforded these watermarks, it has
been
determined that these watermarks may be made larger and that the total area
within
each watermark occupied by reduced fiber density regions (i.e., first regions)
may be
increased and that these regions may be made even thinner. Specifically, it
has been
found that these reduced fiber density regions may be produced with
thicknesses as low
as 10 to 15 microns, with total thicknesses ranging from about 10 to about 60
microns.
The total area occupied by these reduced fiber density regions within each
such
watermark ranges from about 5 to about 75 percent (%) of the total area of the
watermark, preferably from about 20 to about 60%. Moreover, the total area
occupied
by each such watermark within a banknote measuring approximately 10,000 square
millimeters (mm2) may range from about 5 to about 25%, which denotes an
increase in
size compared to conventional watermarks of about 5%.
[0016] The present inventors have also made the surprising discovery
that
micro-optic devices such as the MOTIONTm device may also offer a machine
detectable/readable feature in the form of enhanced IR-brightness, especially
when
measured in transmission. The term "enhanced IR-brightness", as used herein,
is
intended to mean IR-transmission levels of at least 5% greater than
(preferably, more
than 10% greater than) the IR-transmission levels of the background paper. IR-
transmission levels may be measured by using an optical sensor with a
sensitivity at or
above 830 nanometers (nm) and by projecting an IR light source with a
wavelength
greater than 800 nm through the sample. To render IR-brightness a reliable
machine
readable feature, it is preferred that the micro-optic device be made using
one or more
IR-transparent elements (e.g., an IR-transparent ink) and contain no IR-
absorbing
elements (e.g., IR-absorbing inks). It is also preferred that no IR-absorbing
elements be
present in areas close to the device on the front and reverse side of the
paper layer(s).
In one such embodiment, the micro-optic device is a security thread (e.g.,
MOTIONTm
security thread) that contains no IR-absorbing elements. In this embodiment,
the micro-
optic security thread is made using an IR-transparent ink (e.g., ink
comprising non-IR-
absorbing pigments and/or dyes) for the microprint and areas on the front and
reverse
side of the paper layer(s) within at least two-thirds (2/3) of the security
thread's length
contain no IR-absorbing elements.
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[0017] In addition to the at least partially overlying or underlying
micro-optic
device, one or more additional security features may be contained on or within
the first
and/or second regions of the one or more watermarks. In one such embodiment,
the
watermark(s) does not contain one or more polymer or resinous materials within
the first
and/or second regions. The additional security features are selected from the
group of
increased fiber density areas in the form of recognizable or discernible
indicia, one or
more substances that are color-imparting, and one or more second level
security
features that are machine detectable or machine readable, as described above.
[0018] In a second exemplary embodiment, the inventive security paper is
a
multi-ply paper that comprises:
a first paper layer having a reduced basis weight (e.g., from about 10 to
about 50 grams per square meter (gsm)) and including one or more watermarks,
each surface of the first paper layer displaying either the upper or face
portion of
the one or more watermarks or the lower or back portion thereof; and
a second paper layer having a reduced basis weight (e.g., from about 10
to about 50 gsm) and optionally one or more through windows, the second paper
layer covering either the surface of the first paper layer displaying the
upper or
face portion of the one or more watermarks or the surface displaying the lower
or
back portion of the one or more watermarks.
[0019] In one such embodiment, the second paper layer is windowed, the
one or
more through windows in the second paper layer being in register with either
the upper
or face portion or the lower or back portion of the one or more watermarks. By
way of
this second exemplary embodiment, the use of two paper layers and optionally
one or
more overlying or underlying through windows allows for a greater contrast
between the
one or more watermarks and the background. The one or more overlying or
underlying
through windows act in a manner similar to that of an electrotype, occupying
paperless
regions or regions of thinner paper which results in brighter-than-background
regions in
each paper/watermark region.
[0020] In a third exemplary embodiment, one or more security elements in
the
form of one or more color-imparting substances are contained within the first
and/or
second regions of the one or more watermarks. The one or more color-imparting
substances include both dyes and pigments (e.g., ultra-fine particle size
pigments). In
this embodiment, the security sheet or document does not include one or more
film-like
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or foil-like security elements. The resulting watermarks have a tonality
(i.e., color
scheme or range of tones) in a color or shade different from that of the bulk
region of the
material which surrounds the watermark. The inventive watermarks serve to
increase
the perception and resistance to simulation of existing watermarks.
[0021] In a fourth exemplary embodiment, one or more polymer or resinous
materials are contained within the first region(s) and optionally the second
region(s) of
the one or more watermarks. As above, the security sheet or document in this
exemplary embodiment does not include one or more film-like or foil-like
security
elements. The first and/or second regions in this embodiment may also contain
one or
more security features selected from the group of increased fiber density
areas in the
form of recognizable or discernible indicia, one or more substances that are
color-
imparting, and one or more second level security features that are machine
detectable or
machine readable, as described above.
[0022] In a fifth exemplary embodiment, the inventive security sheet or
document
is a single-ply paper that comprises:
a paper layer including one or more watermarks; and
one or more transparent or translucent areas in the paper layer
surrounding each of the one or more watermarks, thereby framing and thus
enhancing the visual perception of the watermark(s).
[0023] Other features and advantages of the invention will be apparent
to one of
ordinary skill from the following detailed description and accompanying
drawings.
[0024] Unless otherwise defined, all technical and scientific terms used
herein
have the same meaning as commonly understood by one of ordinary skill in the
art to
which this invention belongs. All publications, patent applications, patents
and other
references mentioned herein are incorporated by reference in their entirety.
In case of
conflict, the present specification, including definitions, will control. In
addition, the
materials, methods/processes, and examples are illustrative only and not
intended to be
limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present disclosure may be better understood with reference to
the
following drawings. Components in the drawings are not necessarily to scale,
emphasis
instead being placed upon clearly illustrating the principles of the present
disclosure.
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While exemplary embodiments are disclosed in connection with the drawings,
there is no
intent to limit the present disclosure to the embodiment or embodiments
disclosed
herein. On the contrary, the intent is to cover all alternatives,
modifications and
equivalents.
[0026] Particular features of the disclosed invention are illustrated by
reference to
the accompanying drawings in which:
FIG. 1 is an image of a watermark (shield with numeral 30) with overlying
MOTIONTm security patch on or within an exemplary security paper viewed in
daylight
(visible spectrum-reflected light) and under IR-transmitted light from the
face or front side
of the security paper, with the watermark and patch shown at an enlarged scale
for
clarity;
FIG. 2a is another image of the FIG. 1 watermark with overlying security patch
that is again viewed in daylight (visible spectrum-reflected light) and under
IR-
transmitted light from the face side of the security paper, the image enlarged
but to a
lesser degree than FIG. 1, while FIGS. 2b-d are enlarged images of the same
watermark with overlying security patch shown - in IR-transmitted light from
the back
side of the security paper (FIG. 2b), in IR-reflected light from the face side
of the security
paper (FIG. 2c), and in IR-reflected light from the back side of the security
paper (FIG.
2d);
FIG. 3a is another image of the FIG. 1 watermark with overlying security patch
that is viewed in daylight (visible spectrum-reflected light) from the face
side of the
security paper, the image enlarged but to a lesser degree than FIG. 1, while
FIGS. 3b-d
are enlarged images of the same watermark with overlying security patch shown -
in
visible spectrum-reflected light from the back side of the security paper
(FIG. 3b), in
visible spectrum-transmitted light from the face side of the security paper
(FIG. 3c), and
in visible spectrum-transmitted light from the back side of the security paper
(FIG. 3d);
FIG. 4 is a schematic diagram of a modified Fourdrinier or twin-wire paper-
making machine by which watermarks are incorporated along the machine
direction of a
forming paper web via a dandy roll cylinder, and by which a security element
in the form
of an elongate security thread is applied to a surface of the watermarked
paper web
before the wet press section of the machine. The machine employs means for
machine
direction registration of the watermarks and the elongate security thread to
the paper
web. This method for making the inventive sheet material does not displace
fiber
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distribution, resulting in a higher fiber distribution with increased
substrate density and
stiffness which resists deformation, distortion and creasing of the security
thread;
FIG. 5 is a schematic diagram of another modified Fourdrinier or twin-wire
paper-
making machine by which an elongate security thread is fed onto a surface of
the fibrous
web at the same time or right before the watermark(s) is incorporated therein
and before
the wet press section of the machine. The machine employs means for machine
direction registration of the elongate security thread and the watermark(s) to
the fibrous
web. This method for making the fibrous sheet material of the present
invention results
in fiber flowing around the thread, resulting in a lower density fiber
distribution with
reduced density and stiffness under the surface applied thread;
FIG. 6 is a schematic diagram of a paper-making machine made up of two
cylinder paper machines interconnected by a pick-up felt, where an elongate
security
thread contacts a watermarked paper web formed by one cylinder paper machine
before
joining a second paper web formed by the other cylinder paper machine. This
machine
also employs means for machine direction registration of the elongate security
thread
and the watermark(s) to the first paper web;
FIG. 7 provides in a side-by-side comparison enlarged images of a prior art
watermark and an exemplary embodiment of the inventive enhanced watermark,
which
has a strikingly bright or intense appearance;
FIG. 8 provides in a side-by-side comparison enlarged images of an exemplary
embodiment of the inventive watermark which employs a UV excitable second
level
security feature in both transmitted light and under UV light;
FIGS. 9a,b are schematic drawings depicting a method for manufacturing an
exemplary embodiment of the paper security document of the present invention;
FIG. 10 is an enlarged image of a fiber mat or sheet in the wet state on a
papermaking machine (viewed in reflected light on a dark background) with
paper stock
removed in select areas of the sheet with a resultant reduction in fiber
density in those
select areas. The select areas are circular in shape and are shown in two
different
sizes, with the larger sized select areas also containing a circular region of
greater fiber
density; and
FIG. 11a,b are enlarged images of the encircled select area shown in FIG. 10
(viewed in transmitted light) after treatment with one or more polymer or
resinous
materials having an index of refraction or combined index of refraction
substantially
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similar to that of cellulose. The first enlarged image (FIG. 11a) shows the
circular region
within the select area having a color similar to that of the surrounding fiber
mat or sheet,
while the second enlarged image (FIG. 11b) demonstrates that printed material
viewed
under this exemplary embodiment of the inventive security element is clearly
legible.
DETAILED DESCRIPTION OF THE INVENTION
[0027] By way of the present invention, watermarks formed on or within a
security sheet or document are enhanced, rendering the security sheet or
document
more counterfeit-resistant.
[0028] The inventive sheet or document, as noted above, comprises: a
fibrous
sheet material including one or more watermarks; and means for enhancing the
one or
more watermarks by rendering them visually enhanced, machine
detectable/readable, or
both.
[0029] Fibrous sheet materials suitable for use in the present invention
are paper
or paper-like sheet materials. These sheet materials, which are single or
multi-ply sheet
materials, may be made from a range of fiber types including synthetic or
natural fibers
or a mixture of both. For example, these sheet materials may be made from
fibers such
as abaca, cotton, linen, wood pulp, and blends thereof. As is well known to
those skilled
in the art, cotton and cotton/linen or cotton/synthetic fiber blends are
preferred for
banknotes, while wood pulp is commonly used in non-banknote security
documents.
[0030] The watermarks may be formed in the fibrous sheet material using
known
methods and techniques. For example, the watermarked sheet material may be
manufactured on a cylinder mold papermaking machine (using an embossed wire
cloth,
or by applying a thin piece of metal, generally in the form of an image or
letter, to the
wire cloth), or on a Fourdrinier papermaking machine (using a dandy roll).
[0031] Exemplary embodiments of the inventive security sheet or document
in
which various means for enhancing the watermark(s) are employed, and their
respective
methods of manufacture will now be discussed.
[0032] In a first exemplary embodiment, the inventive security sheet or
document
is a single- or multi-ply paper that comprises (a) a first paper layer
including one or more
watermarks, each surface of the paper layer displaying either the upper or
face portion
of the watermark(s) or the lower or back portion thereof, (b) one or more film-
like or foil-
like security elements having a color different from the watermark(s) that at
least partially
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covers the upper or face portion or the lower or back portion of the
watermark(s), and
optionally (c) a second paper layer having a reduced basis weight compared to
the first
paper layer (e.g., from about 10 to about 50 gsm) and optionally one or more
through
windows, the second paper layer covering either the upper or face portion or
the lower or
back portion of the watermark(s).
[0033] The film-like or foil-like security element(s) used in the
practice of the
present invention is limited only by its film-like or foil-like structure,
with contemplated
structures having total thicknesses ranging from about 15 to about 100 microns
(preferably, from about 15 to about 50 microns). The film-like or foil-like
structures may
take any shape including, but not limited to, bands, strips, stripes, threads,
or patches.
They may display or project information that is humanly perceivable either
directly or
with the aid of a device and/or embody information that is detectable/readable
by
machine. The structures may be segmented into regions, with the information
being
displayed or projected or otherwise contained in some or all of these regions
being the
same or different.
[0034] Suitable film-like or foil-like security elements may employ one
or more of
the following: demetalized or selectively metalized, magnetic, combined
magnetic and
metallic, or embossed (e.g., blind embossed) regions or layers, color changing
coatings
made up of color shift, iridescent, liquid crystal, photochromic and/or
thermochromic
materials, coatings of luminescent and/or magnetic materials, holographic
and/or
diffractive security features, and micro-optic security features.
[0035] In a preferred embodiment, the security element(s) is a micro-
optic
structure. As noted above, such structures project one or more synthetically
magnified
optical images, and generally comprise: (a) a light-transmitting polymeric
substrate; (b)
an arrangement of micro-sized image icons located on or within the polymeric
substrate;
and (c) an arrangement of microlenses. The icon and microlens arrangements are
configured such that when the arrangement of icons is viewed through the
arrangement
of microlenses, one or more synthetically magnified optical images are
projected. These
projected images may show a number of different optical effects. Such
structures are
described in U.S. Patent No. 7,333,268 to Steenblik et al., U.S. Patent No.
7,468,842 to
Steenblik et al., U.S. Patent No. 7,738,175 to Steenblik et al., International
Patent
Publication Number WO 2005/106601 A2 to Commander et al., and International
Patent
Publication Number WO 2007/076952 A2 to Kaule et al. In one such embodiment, a
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micro-optic structure as described in U.S. Patent No. 7,333,268 to Steenblik
et al. is
employed (e.g., the MOTIONTm micro-optic security device), the structure being
formed
from a polymeric substrate prepared using one or more essentially colorless
polymers
selected from the group including, but not limited to, polyester,
polyethylene,
polyethylene terephthalate, polypropylene, polyvinyl carbonate, polyvinylidene
chloride,
and combinations thereof.
[0036] In a more preferred embodiment, the micro-optic security device
is in the
form of a surface-applied patch that covers all or part (e.g., one-half) of a
watermark, the
watermark containing one or more polymer or resinous materials within the
first and/or
second regions thereof, the one or more polymer or resinous materials having
an index
of refraction or combined (final) index of refraction substantially similar to
that of
cellulose. The first and/or second regions of the watermark may also contain
one or
more features selected from the group of increased fiber density areas in the
form of
recognizable or discernible indicia, one or more substances that are color-
imparting, and
one or more second level security features that are machine detectable or
machine
readable, as described above.
[0037] In another more preferred embodiment, the micro-optic security
device is
in the form of a surface-applied elongate strip or thread, or a partially
embedded
elongate security strip or thread that is present in window regions of a
second paper
layer (i.e., windowed thread). The strip or thread in this embodiment covers
all or part of
the watermark(s).
[0038] In yet a more preferred embodiment, the micro-optic security
device (e.g.,
the MOTIONTm device) is designed such that when registered with the watermark,
synthetic images projected thereby are combined with the watermark design. For
example, in the above-referenced embodiments, the synthetic image(s) generated
by
each patch or thread may coordinate or link in with the watermark design. The
synthetic
image(s) may also complete the watermark design(s) or locate within the
design(s). This
may be a one-sided or two-sided feature. In other words, complete information
intended
to be conveyed to the viewer is not supplied solely by the watermark or
synthetic
image(s), but requires that both be viewed simultaneously. In one such
example, when
viewed at the optimal (perpendicular) viewing angle using visible spectrum-
transmitted
light, the MOTIONTm patch projects a synthetic image in the form of a coat of
arms that
overlays (in register) the watermark design in the form of a shield. When the
viewing
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angle is moved off-axis, the synthetic image and the watermark design are no
longer in
register with each other, and one would see the watermark design (shield and
numeral
30) within the patch and the synthetic image would transition or switch from
the coat of
arms to, for example, an array of numerals.
[0039] An inherent benefit in the exemplary embodiments of the present
invention which employ a partially or fully overlying or underlying film-like
or foil-like
security element such as the MOTIONTm micro-optic security device is the
increased
durability of each watermark. Covering all or part of the watermark(s) with an
applied
film, foil, band, strip, stripe, thread, or patch serves to physically protect
the watermark(s)
from damage during circulation and handling, thus increasing its durability.
[0040] Due to the increased durability afforded these watermarks, it has
been
determined that these watermarks may be made larger and that the total area
within
each watermark occupied by reduced fiber density regions (i.e., first regions)
may be
increased and that these regions may be made even thinner. Specifically, it
has been
found that these reduced fiber density regions may be produced with
thicknesses as low
as 10 to 15 microns, with total thicknesses ranging from about 10 to about 60
microns.
The total area occupied by these reduced fiber density regions within each
such
watermark ranges from about 5 to about 75 percent (%) of the total area of the
watermark, preferably from about 20 to about 60%. Moreover, the total area
occupied
by each such watermark within a banknote measuring approximately 10,000 mm2
may
range from about 5 to about 25%, which denotes an increase in size compared to
conventional watermarks of about 5%.
[0041] The present inventors have also made the surprising discovery
that
micro-optic devices such as the MOTIONTm device may also offer a machine
detectable/readable feature in the form of enhanced IR-brightness, especially
when
measured in transmission. To render IR-brightness a reliable machine readable
feature,
it is preferred that the micro-optic device be made using one or more IR-
transparent
elements (e.g., an IR-transparent ink) and contain no IR-absorbing elements
(e.g., IR-
absorbing inks). It is also preferred that no IR-absorbing elements be present
in areas
close to the device on the front and reverse side of the paper layer(s).
[0042] Referring now to FIG. 1, one such embodiment of the inventive
security
sheet or document is shown and marked with reference numeral 10). The micro-
optic
device is a MOTIONTm security patch 12 that contains no IR-absorbing elements.
The
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patch 12 is located over a watermark 14 in the shape of a shield in which dark
regions
formed by more densely deposited fibers than the normal base fiber density
(i.e., second
regions) 16 occupy the outer perimeter, light regions formed by less densely
deposited
fibers than the normal base fiber density (i.e., first regions) 18 occupy the
area inside the
shield design with the region occupied by the numeral 30 formed by even
lighter or less
dense regions. The watermark 14 with overlying MOTIONTm security patch 12 in
FIG. 1
is shown in daylight and under IR-transmitted light, with the watermark and
patch
illustrated at an enlarged scale for clarity.
[0043] As will be readily apparent from viewing FIG. 1, the numeral 30
is very
bright as a result of the overlying patch. Here, IR-brightness correlates to
the strength of
the IR-signal, which as noted above is measured in transmission by using an
optical
sensor with a sensitivity at or above 830 nm and by projecting an IR light
source with a
wavelength of greater than 800 nm through the sample. IR-brightness may be
controlled
by the IR-properties of the ink used for the microprint of the security patch
12. The
microprint in the form of micro-sized image icons located on or within a
polymeric
substrate is made using a printing method (e.g., ink jet, laserjet,
letterpress, flexo,
gravure, intaglio, and dye sublimation printing methods), or using a
microstructure
approach. In the latter case, the image icons would be made as voids or
recesses in the
substrate (e.g., recesses measuring, for example, from about 0.5 to about 8
microns in
total depth), or as raised structures relative to the substrate (e.g., raised
structures
(colored or colorless) measuring, for example, from about 0.5 to about 8
microns in total
height). An IR-transparent material (e.g., ink comprising non-IR-absorbing
pigments
and/or dyes) would be used to form the icons by, for example, printing,
coating or
partially or completely filling the recesses or areas surrounding the raised
structures, or
forming raised (colored or colorless) structures. It is preferred that areas
on the front
and reverse side of the paper layer(s) within a distance of approximately 5
millimeters
from an outer edge of the patch would contain no IR-absorbing elements.
[0044] In regard to the appearance of the FIG. 1 embodiment, and as
shown in
FIGS. 2a-d and 3a-d:
(a) In IR-transmission or IR-transmitted light from the front or face
of the
document, one would see the watermark (shield and the numeral 30) and a faint
patch
overlay (see FIG. 2a);
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(b) In IR-transmission from the back of the document, one would see the
watermark (shield and the numeral 30) in reverse and a darker patch overlay
(see FIG.
2b);
(c) In IR-reflected light from the face of the document, one would see the
watermark (outline only) and a faint patch overlay (see FIG. 2c);
(d) In IR-reflected light from the back of the document, one would not see
either the watermark or the patch overlay (see FIG. 2d);
(e) In visible spectrum-reflected light, from the face of the document, one
would see the one or more synthetic images but not the watermark (or only a
faint
outline of the watermark) (see FIG. 3a);
(f) In visible spectrum-reflected light, from the back of the document, one
would see the watermark as dark (see FIG. 3b);
(g) In visible spectrum-transmitted light, from the face of the document,
one
would see the combined image of the watermark and the one or more synthetic
images
(see FIG. 3c); and
(h) In visible spectrum-transmitted light, from the back of the document,
one
would see the watermark (shield and the numeral 30) in reverse with a colored
overlay
of the patch, but not the projected synthetic image(s) (see FIG. 3d).
[0045] As mentioned above, in addition to the at least partially
overlying or
underlying micro-optic device, one or more additional security features may be
contained
on or within the first and/or second regions of the one or more watermarks. In
one such
embodiment, the watermark(s) does not contain one or more polymer or resinous
materials within the first and/or second regions. The additional security
features are
selected from the group of increased fiber density areas in the form of
recognizable or
discernible indicia, one or more substances that are color-imparting, and one
or more
second level security features that are machine detectable or machine
readable, as
described above.
[0046] Reference is now made to methods or techniques for making the
first
exemplary embodiment in which a fibrous sheet material with a film-like or
foil-like
security element is registered in the machine direction (MD) with respect to
one or more
watermarks contained or formed in the sheet material.
[0047] The film-like or foil-like security elements may be embedded
(when in the
form of, for example, a security strip or thread) in a second paper layer, or
applied to a
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surface of the watermarked paper layer or second paper layer (when in the form
of, for
example, a thread or patch) using known methods and techniques. For example,
the
security element(s) (with one or more adhesive layers) may be transferred to a
surface
of the watermarked or second paper layer as a transfer film using techniques
including
mechanical, chemical, thermal and photo-induced separation techniques. The
concept
of separation of desired components from a carrier substrate is known in the
art of
holographic foil transfer, whereby a film with a release coating (i.e.,
release liner) is
provided with coatings (e.g., optical) and adhesives, such that the coatings
and
adhesives can be transferred to a final substrate with application of heat and
pressure.
This approach is particularly useful in applications requiring films with very
thin cross-
sectional thicknesses.
[0048] Activatable adhesives may be used to anchor or bond the film-like
or foil-
like security elements onto or within a surface of the fibrous sheet material.
Suitable
adhesives are not limited and include, but are not limited to, water-, heat-
and/or
pressure-activating adhesives that activate in the secondary dryer section of
the
papermaking machine, where temperatures reach between 100 C and 160 C. These
coatings may be applied in the form of solvent-based polymer solutions or
aqueous
solutions or dispersions. Suitable dispersions are selected from the group of
acrylic
resin dispersions, epoxy resin dispersions, natural latex dispersions,
polyurethane resin
dispersions, polyvinyl acetate resin dispersions, polyvinyl alcohol resin
dispersions, urea
formaldehyde resin dispersions, vinyl acetate resin dispersions, ethylene
vinyl acetate
resin dispersions, ethylene vinyl alcohol resin dispersions, polyester resin
dispersions,
and mixtures thereof.
[0049] Machine direction registration of security patches to watermarks
contained on or formed in the sheet material may be achieved by indexing the
relative
position of the watermark(s) on the equipment used to produce the watermark(s)
in the
paper sheet. The watermark(s) position is then conveyed in a continuous manner
to the
equipment used to apply the security patch(es) to the paper surface. Pre-
applied marks
or indexes on the carrier film used to convey the patch(es) is used to control
the speed
of the carrier film and thus the patch(es), thereby ensuring registration of
the
watermark(s) with the patch(es).
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[0050] Machine direction registration of a security thread to watermarks
contained on or formed in the sheet material will now be described in
conjunction with
FIGS. 4 to 6.
[0051] In FIG. 4, a Fourdrinier process for making a single-ply
embodiment of
the fibrous sheet material of the present invention is shown. In this process,
an
adhesive coated security thread 20 (oriented such that the front side of the
security
thread and not the adhesive coated back side is an uppermost layer) is guided
along a
tube 22 with a variable speed advancing device 24 (e.g., electric
servomechanism with
servo drive) and pushed into a surface of a partially consolidated advancing
fibrous web
26 (e.g., a fibrous slurry containing from about 1 to about 10 % by weight
stock and from
about 99 to about 90 % by weight water) at the wet end 28 of the paper-making
machine
after the web 26 has been watermarked by a dandy roll cylinder 30. Here, the
security
thread 20 may be positioned either partially or completely on top of the
watermark(s)
(i.e., layered security features) on the surface of the web 26. As will be
readily
appreciated by those skilled in the art, the dandy roll cylinder 30 may be
provided with
raised and/or recessed areas on its surface, which may fully or partially
overlap the area
on the surface of the web 26 that will be occupied by the thread 20.
[0052] It is noted that this embodiment of the inventive method does not
serve to
disrupt fiber distribution around the surface applied security thread,
resulting in a higher
density fiber distribution with increased substrate density and stiffness
which resists
security thread deformation, distortion and creasing.
[0053] As water continues to drain from web 26, the fibers form around
the
thread 20 holding it in place on a front or upper surface of web 26. Upon
leaving the wet
end 28, the fibrous web 26 is passed through the press, main and secondary
dryer and
calender sections of the paper-making machine. While in the secondary dryer
section of
the paper-making machine, the web 26 is exposed to temperatures and/or
pressures
sufficient to activate the security thread's adhesive coating, causing it to
firmly bond the
thread in the fibrous sheet material, with the security thread continuously
exposed on a
front or upper surface of the sheet material partially or fully covering the
formed
watermark(s), while concealed from view on a back or lower surface of the
sheet
material.
[0054] Machine directional registration of the security thread 20 to the
formed
watermark(s) is achieved using conventional techniques commonly used in the
art. For
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example, and as best shown in FIG. 4, an automatic registration control system
for a
papermaking machine is used, which includes the variable speed security thread
advancing device 24, optical sensors 32a, 32b for tracking registration marks
on the
dandy roll cylinder 30 and on the security thread 20, and an encoder wheel 34
for
tracking the speed of the paper being formed on the machine.
[0055] As
the forming web 26 moves through the wet end 28 of the papermaking
machine, registration marks placed on the dandy roll cylinder 30 and on the
security
thread 20 are continuously tracked by the optical sensors 32a, 32b, thereby
continuously
determining/monitoring the position of the security thread 20 being fed
through the tube
22 and advancing device 24 and the position of the watermark(s) relative to an
edge of
the forming web 26, while the speed of the paper being formed is tracked by
the encoder
wheel 34. Signals are produced from the position and speed determinations and
the
speed and position of the advancing device 24 adjusted on the basis of those
signals in
such a way that the security thread 20 and the watermark(s) are registered
along the
machine direction of the web 26.
[0056] In
another embodiment of the inventive method, which is shown in FIG. 5,
the adhesive coated security thread 20 (again oriented such that the security
thread and
not the adhesive coating is an uppermost layer) is guided through the variable
speed
advancing device 24 and past optical sensor 32b and then pushed into a surface
of the
partially consolidated forming fibrous web 26 by the dandy roll 30 at the wet
end 28 of
the paper-making machine, the dandy roll 30 simultaneously or subsequently
watermarking the web 26. It is noted that by way of this embodiment of the
inventive
method, fiber flows around the security thread, resulting in a lower density
fiber
distribution with reduced substrate density and stiffness under the thread.
[0057]
Similar to that noted above, as the forming web 26 moves through the wet
end 28 of the papermaking machine, registration marks placed on the dandy roll
cylinder
30 and on the security thread 20 are continuously tracked by the optical
sensors 32a,
32b, thereby continuously determining/monitoring the position of the
watermark(s) and
the position of the security thread 20 being applied to a surface of the web
26 relative to
an edge of the forming web 26, while the speed of the paper being formed is
tracked by
the encoder wheel 34.
Signals are produced from the position and speed
determinations and the speed and position of the advancing device 24 adjusted
on the
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basis of those signals in such a way that the security thread 20 and the
watermark(s) are
registered along the machine direction of the web 26.
[0058] A cylinder mold process for making a two-ply embodiment of the
fibrous
sheet material of the present invention is shown in FIG. 6. In this process,
which
employs two cylinder paper machines 36a, 36b, interconnected by pick-up felt
38, two
paper webs 40, 42, are formed simultaneously, squeezed together in the area of
roller
44, and then fed together to the press, dryer and calender sections of the
paper-making
machine. The resulting fibrous sheet material has the same physical
characteristics as
those noted above for sheet materials made using a Fourdrinier process. As
will be
readily appreciated by those skilled in the art, while FIG. 6 shows cylinder
paper
machines of the wet vat type, cylinder paper machines of the dry vat type may
also be
used to make the fibrous sheet material of the present invention.
[0059] The two-ply paper web 46, formed by the cylinder paper machines
shown
in FIG. 6, has adhesive coated security thread 20 recessed and one or more
watermarks
formed in a surface thereof, with the security thread 20 and the watermark(s)
fully
viewable from this surface. The watermark(s) is formed in paper web 40 by
forming
cylinder 48 and then the security thread 20 is integrated into the paper web
by directing
the thread through the variable speed advancing device 24 and past optical
sensor 32b
and then between roller 50 and a surface of the paper web exiting cylinder
paper
machine 36a. Here, the security thread 20 may be positioned partially or
completely on
top of the watermark(s) on the surface of the paper web. Paper web 40 with
surface
applied security thread 20 and watermark(s) is then directed between roller 44
and a
surface of the second paper web 42 exiting cylinder paper machine 36b, where
the two
paper webs are squeezed together. The second paper web 42 is homogeneous and
serves to hide any irregularities in paper formation on a back or lower
surface of the first
paper web 40 that may have been caused by the presence of thread 20.
[0060] As alluded to above, forming cylinder 48 may be provided with
raised
and/or recessed areas on its surface, which may fully or partially overlap the
area
contacted by thread 20 during manufacture.
[0061] As in previous embodiments, machine directional registration
between the
security thread 20, the watermark(s) and the paper web 40 is achieved by the
variable
speed security thread advancing device 24, optical sensors 32a, 32b for
tracking
registration marks on the forming cylinder 48 and on the security thread 20,
and an
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encoder wheel 34 for tracking the speed of the paper being formed on cylinder
paper
machine 36a.
[0062] Upon exiting the calender section of any of the above-referenced
paper-
making machines, the inventive fibrous sheet material may be wound up and
stored or
directly introduced into another machine (e.g., a printing machine) for
further processing.
[0063] In a second exemplary embodiment, the inventive security paper is
a
multi-ply paper that comprises:
a first paper layer having a reduced basis weight (e.g., from about 10 to
about 50 gsm) and including one or more watermarks, each surface of the first
paper layer displaying either the upper or face portion of the one or more
watermarks or the lower or back portion thereof; and
a second paper layer having a reduced basis weight (e.g., from about 10
to about 50 gsm) and optionally one or more through windows, the second paper
layer covering either the surface of the first paper layer displaying the
upper or
face portion of the one or more watermarks or the surface displaying the lower
or
back portion of the one or more watermarks.
[0064] In one such embodiment, the second paper layer is windowed, the
one or
more through windows in the second paper layer being in register with the one
or more
watermarks. By way of this second exemplary embodiment, the use of two paper
layers
and optionally one or more overlying through windows allows for a greater
contrast
between the one or more watermarks and the background.
[0065] In a third exemplary embodiment, one or more security elements in
the
form of one or more color-imparting substances are contained within the first
and/or
second regions of the one or more watermarks. The one or more color-imparting
substances include both dyes and pigments (e.g., ultra-fine particle size
pigments). As
noted above, in this embodiment, the security sheet or document does not
include one
or more film-like or foil-like security elements. The resulting watermarks
have a tonality
(i.e., color scheme or range of tones) in a color or shade different from that
of the bulk
region of the material which surrounds the watermarks, which serves to
increase their
perception and resistance to simulation.
[0066] Watermarks have traditionally been the same color as the paper
substrate on or within which they are carried. These marks are formed by
localized
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variation in the thickness of the paper that changes the opacity of the paper,
making the
watermark visible in transmitted light or in reflected light atop a dark
background.
[0067] A prior art or standard watermark is shown against the same color
paper
substrate in FIG. 7. Here, only a marginal contrast between light and dark
areas in the
watermark is evident rendering the watermark more difficult to detect. By way
of
comparison, as also shown in FIG. 7, the enhanced watermark of the present
invention,
which includes one or more color-imparting substances in the form of one or
more visible
(colored) pigments (i.e., blue), has improved quality in which the contrast
between the
light and dark areas in the watermark is significantly greater. The public's
attention is
therefore drawn more readily to the inventive watermark increasing the
effectiveness of
this security feature.
[0068] Another exemplary embodiment of the present invention is shown in
FIG.
8. Here, the inventive watermark contains a second level security feature in
the form of
a UV excitable substance in addition to one or more color-imparting
substances. The
inventive watermark not only demonstrates a marked contrast between light and
dark
areas in transmitted light, but because it also contains a substance which can
be excited
by UV radiation, it also demonstrates a tonality of UV response that is
difficult to
reproduce, thereby rendering this watermark embodiment even more counterfeit
resistant.
[0069] Referring now to FIG. 9, in an exemplary embodiment in which the
security sheet or document is a paper security document, the inventive method
for
manufacturing the security document involves making a continuous roll of
watermarked
paper 52 on a paper making machine 54 (FIG. 9a), watermarks or watermark
regions 56
repeating along the length of the paper (FIG. 9b), each having lower grammage
areas
(i.e., first regions) and higher grammage areas (i.e., second regions), so as
to provide
lighter and darker areas in the watermark regions 56, the method comprising:
applying a colored solution 58 comprising color-imparting substances to
the plurality of watermark regions 56 on one side of the continuous roll of
paper
while applying a vacuum to an opposing side of the paper to pull the applied
colored solution into the paper,
wherein, higher grammage areas of the watermark regions 56 hold more color-
imparting substances while lower grammage areas hold less color-imparting
substances,
thereby providing the watermark regions tonality in a color or shade different
from that of
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bulk regions of the paper surrounding the plurality of watermark regions
repeating along
its length.
[0070] As previously noted, the watermarks are formed by well-known
techniques on, for example, a cylinder mold papermaking machine or a
Fourdrinier
papermaking machine (using a dandy roll). A range of fiber types can be used
in making
the paper, including synthetic or natural fibers or a mixture of both.
[0071] The "colored solution" used to impart tonality to the watermarks
of the
present invention comprises the one or more color-imparting substances
referred to
above, which include both dyes and pigments (e.g., ultra-fine particle size
pigments).
[0072] After forming watermarks on the paper machine 54, the colored
solution
58 is applied locally to the watermark regions 56 of the paper while the paper
is still wet
and on a forming wire and before any wet pressing occurs. The colored solution
may be
applied to the continuous roll of watermarked paper 52 using a low volume
intermittent
shower with nozzles 60 aligned to the watermark regions of the paper. The
colored
solution is drawn into the paper web using one or more vacuum boxes 62.
Although two
vacuum boxes are shown in FIG. 9b, one or more vacuum boxes may be used in the
practice of the inventive method.
[0073] In a fourth exemplary embodiment, which will be referred to as
the 'see-
through' watermark embodiment, one or more polymer or resinous materials are
contained within the first region(s) and optionally the second region(s) of
the one or more
watermarks. As noted above, the security sheet or document in this exemplary
embodiment does not include one or more film-like or foil-like security
elements. The
first and/or second regions in this embodiment may also contain one or more
security
features selected from the group of increased fiber density areas in the form
of
recognizable or discernible indicia, one or more substances that are color-
imparting, and
one or more second level security features that are machine detectable or
machine
readable, as described above.
[0074] The see-through watermark embodiment of the present invention
provides an easily recognized public security feature for first-level
authentication. The
inventive watermark(s), which may be a paper-borne feature, allows for
authentication
by its transmissive properties. The inclusion of such a translucent or
transparent region
within a security document (e.g., banknote) cannot be replicated with
scanning, image
analysis, and subsequent digital reproduction techniques.
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[0075] In an exemplary embodiment, the inventive see-through
watermark(s) is
obtained as part of the papermaking process during sheet formation in the wet
state.
For example, a paper web is made in a continuous manner on a Fourdrinier
papermaking machine. Paper stock is deposited from a head box onto a
continuous
moving wire mesh. Water from the paper stock then drains through the wire mesh
leaving a wet de-watered fiber mat.
[0076] The inventive see-through watermark(s) is formed by first
removing paper
stock from select areas of the fiber mat with a resultant reduction in fiber
density (see
FIG. 10). This may be done using conventional techniques such dandy roll (or
cylinder
vat) technology. The select areas with lower fiber density (i.e., the first
regions) have
reduced opacity relative to other areas of the watermark(s) (i.e., the second
regions) and
other areas of the fiber mat (i.e., the base sheet), though not transparent.
Next, the first
and optionally the second regions of the watermark(s) are treated with one or
more
polymer or resinous materials chosen for a final refractive index which
closely matches
cellulose (e.g., a UV curable, e-beam curable, or thermal curable polymer or
resinous
material).
[0077] The first and second regions may be treated with the one or more
polymer or resinous materials on the papermaking machine, in an off-line web
process
such as rewinding or respooling, in a dedicated off-line web process prior to
sheet
cutting, or on individual sheets.
[0078] The one or more polymer or resinous materials, which saturate the
paper
in the first and optionally the second regions of the watermark(s) (replacing
air in the
interstices between fibers), may optionally be applied in a pattern over these
areas, and
may further be cured via radiation, thermal/catalytic, or oxidative means.
[0079] As best shown in FIGS. 11a,b, transmission of visible light is
now
possible through the resulting translucent or transparent see-through
watermark(s). As
a result, printed material viewed under the see-through watermark(s) is
clearly legible.
[0080] The choice of a polymer or resinous material(s) of appropriate
modulus
may also allow for embossing, applications within the translucent or
transparent areas to
be performed, for example, prior to printing, or during an intaglio printing
process.
[0081] The inventive see-through watermark(s) may also include one or
more
features within its perimeter selected from the group of increased fiber
density areas in
the form of recognizable or discernible indicia, one or more substances that
are color-
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imparting, and one or more second level security features that are machine
detectable or
machine readable, as described above.
[0082] These features in the form of, for example, fibers or planchettes
may be
added via random addition to the papermaking furnish, or selectively placed in-
line in the
position of the see-though security element. In addition, or alternatively,
such inclusions
could be concentrated in specific cross-direction areas of the paper.
[0083] In a fifth exemplary embodiment, the inventive security sheet or
document
is a single-ply paper that comprises:
a paper layer including one or more watermarks; and
one or more transparent or translucent areas in the paper layer
surrounding each of the one or more watermarks, thereby framing and thus
enhancing the visual perception of the watermark(s).
[0084] Such frame-like areas may be formed in the watermarked paper
layer by
treating the areas surrounding each watermark with one or more
transparentizing
polymer or resinous materials, such as a UV curable, e-beam curable, or
thermal
curable polymer or resinous material.
[0085] These frame-like areas may be treated with the transparentizing
material(s) on the papermaking machine, in an off-line web process such as
rewinding or
respooling, in a dedicated off-line web process prior to sheet cutting, or on
individual
sheets.
[0086] The transparentizing material(s) saturates the paper in the
applied areas
replacing air in the interstices between fibers. This material(s) may be
curable or non-
curable. Treated areas of the watermarked paper layer allow for the
transmission of
visible light, thereby framing and thus enhancing the visual perception of
watermark(s).
[0087] While various embodiments of the present invention have been
described
above it should be understood that they have been presented by way of example
only,
and not limitation. Thus, the breadth and scope of the present invention
should not be
limited by any of the exemplary embodiments.
[0088] The invention claimed is:
