Patent Application
20100181020
1. Field of the Invention
The present invention relates generally to the field of self-adhesive film assemblies for application to windows to make vision control panels, for example one-way vision panels having a design on one side which is not visible from the other side, the other side allowing through vision.
2. Description of Related Art
Vision control panels are well known, for example panels having a design superimposed on an opaque silhouette pattern as disclosed in U.S. RE37,186 and panels having a design superimposed on a translucent “base pattern”, which enables the design to be illuminated from the other side of the panel, as disclosed in U.S. Pat. No. 6,212,805. Both of these patents disclose self-adhesive assemblies comprising a light-permeable film facestock layer, an adhesive layer and a removable protective film layer, sometimes referred to as a liner or release liner. Such self-adhesive assemblies include facestock film which is perforated vinyl, or vinyl cut into discrete, elongated areas, for example stripes, or non-perforated clear film.
In September 1993 Visual Technologies, Inc., N.C., USA, made public the application of an additional non-perforated backing layer to the perforated liner of a perforated self-adhesive vinyl assembly, as also disclosed in U.S. Pat. No. 5,773,110 and U.S. Pat. No. 5,609,938. The benefits of an assembly with a non-perforated backing layer are various, including the ability to hold the assembly with a vacuum suction device, for example on the bed of a screen printing press, and to prevent ink from a digital inkjet printing press passing though the perforation holes, for example onto a printing press platen. U.S. Pat. No. 5,858,155 discloses a non-perforated replacement liner applied to a perforated adhesive layer after removal of a temporary perforated liner, to achieve the same and additional benefits.
Such products are sometimes referred to as perforated base materials or perforated self-adhesive assemblies or perforated film assemblies or perforated self-adhesive films and are typically imaged by one of a number of printing techniques, including screen printing and various digital imaging methods, for example inkjet printing, electrostatic transfer printing and thermal mass transfer printing or sublimation. A perforated film assembly for subsequent application to the outside of a window typically has a white-on-black facestock, or a white facestock in conjunction with a black adhesive. An additional non-perforated backing layer is typically provided by a white self-adhesive “application tape” or by a heat-bonded film, for example a colorless, polypropylene film. A replacement liner is typically white or clear, typically a white, silicone-coated paper or a silicone-coated clear polyester. When imaged with a design, following removal of the liner and application to a window, the design is typically intended to be seen from outside the window, for example of a building or vehicle, illuminated by natural daylight. Designs such as advertisements or signs are typically seen, therefore, against a relatively dark background of the interior of the building or vehicle. Known techniques of “undercolor removal” of inks have been used to compensate for this background darkening effect, also disclosed in PCT/US96/09888.
Perforated static cling film assemblies with a non-perforated liner and no adhesive layer are also known.
U.S. Pat. No. 6,552,820 discloses a method of printing a vision control panel in which a transparent substrate is partially printed with an opaque print pattern, for example a print pattern of lines. An optical scanning device identifies leading and trailing edges of the select areas of printing and instructs a digital printing machine to print a superimposed layer, typically a design, on areas of the print pattern, for example a pattern of opaque white on black lines orientated perpendicular to the direction of primary movement of inkjet printheads, which are recognised in contrast to the transparent substrate that is unprinted between the opaque printed lines.
U.S. Pat. No. 5,250,336 (Greuse) discloses the use of a liner of contrasting color in a self-adhesive assembly in the field of kiss-cut, self-adhesive labels, to enable the quality of the cutting of the edges of kiss-cut labels to be more easily assessed following “weeding” of the surrounding unwanted facestock material.
When imaging various of the above-discussed (and/or other) products, there is a problem that the printed image appearance, when seen against a white or clear imperforate layer, appears to be “washed out” or weak in visual impact. If the design is printed by a method which deposits ink through the perforation holes onto an imperforated layer which does not have an ink-receptive surface, for example a silicone coating to a release liner or an adhesive coating to an application tape used as a non-perforated layer, the ink or other marking material does not have normal coverage. For example, if the design is solvent inkjet printed, the ink typically does not adhere to and coalesces or forms globules or otherwise does not cover all the white or clear solid layer. No image is applied to the hole areas with electrostatic or thermal transfer printing. This reduction in imaged area does not give a good visual impression of the product before application to a window and does not properly represent its final appearance. As a result, print operators are known to apply more design colorants than are actually required or desirable in the finished product, for example unnecessarily repeating applications of inkjet printing, in order to seek to obtain a better visual appearance upon printing. Apart from being excessively costly and visually unnecessary and/or visually undesirable in the finished product, the application of excessive ink is not desirable environmentally, for example because of solvents being emitted from the imaged product, either locally or in a global context, or in the energy consumption of curing solvent ink.
Also, a curing regime suited to the imaging surface is typically not as effective at the bottom of the perforation holes, on top of the solid liner surface. There is the possibility that uncured inks, for example solvent inkjet inks lying on the non-perforated layer, have a deleterious effect on the other materials in the assembly, for example by solvents attacking the pressure-sensitive adhesive layer.
A similar problem exists with vision control panels comprising cut film, for example self-adhesive vinyl lines or “stripes” disposed on a “solid” release liner, typically a white, silicone-coated paper, as disclosed in U.S. RE37,186, U.S. Pat. No. 6,212,805, U.S. Pat. No. 6,267,052, U.S. Pat. No. 6,899,775 and U.S. Patent Application 60/727,462 and with vision control panels comprising a clear, transparent imperforate self-adhesive film, for example as disclosed in U.S. RE37,186, U.S. Pat. No. 6,212,805, U.S. Pat. No. 6,210,776, U.S. Pat. No. 6,552,820, U.S. Pat. No. 6,506,475, U.S. Pat. No. 6,267,052 and U.S. Pat. No. 6,899,775.
Conversely, UV cured inks, for example applied by a digital inkjet machine, may be cured on a white or clear non-perforated liner component of a perforated or cut film self-adhesive assembly and give the visual impression, before the liner is removed, of a design applied over a continuous white or clear surface. This provides an overly bold impression of the design compared to the reduced impact caused by removal of the liner and application of the imaged perforated or cut film to the window of a building or vehicle with a relatively dark interior compared to external daylight.
One or more embodiments of the present invention overcome one or more of the above-discussed deficiencies of the prior art by providing a contrasting color release liner. Such a contrast may improve the perception of the design on an imaged self-adhesive film assembly used for making a vision control panel:
(A) when first printed on the self-adhesive film assembly compared to the paler, “washed out”, “whitened” or otherwise weaker appearance of a design printed on a prior art self-adhesive film assembly with a white or colorless release liner, thus tending to reduce the common prior art practice of print operatives applying more ink than is necessary or desirable, in order to achieve a stronger image,
(B) when observed as an imaged self-adhesive assembly, for example by a customer, before removal of the liner, thus reducing and/or eliminating the paler, washed out, whitened or otherwise weaker appearance of the imaged prior art products, and
(C) so that it will more closely resemble the finished vision control panel or see-through graphic panel following removal of the release liner and application of the imaged light permeable film layer to a window, the window typically having a relatively dark interior background against which the design is observed.
According to one embodiment of the present invention, an assembly comprises a light-permeable film layer, a release liner, and a print pattern, said print pattern comprising a base layer, said base layer comprising:
(i) a perforated film,
(ii) a cut film layer, said cut film layer cut into a plurality of elongate film layer areas, or
(iii) marking material applied to an imperforate transparent film,
said print pattern sub-dividing said film layer into a plurality of discrete base layer areas and/or a plurality of transparent areas, said base layer comprising a design imaging surface of a first color, said release liner comprising an imperforate material, said release liner comprising a release surface,
characterized in that said imperforate material when viewed through said light permeable film layer comprises a second color contrasting with said first color by the graytone of said second color differing from the graytone of said first color by at least 10%.
Another embodiment of the invention comprises a method of making an assembly, said assembly comprising a light permeable film layer, a release liner, and a print pattern, said print pattern comprising a base layer, said print pattern subdividing said assembly into a plurality of discrete base layer areas and/or a plurality of discrete transparent areas, said base layer comprising a design imaging surface of a first color, said method comprising:
(i) providing a self-adhesive assembly comprising a facestock film layer and an initial release liner removably attached to said facestock film layer,
(ii) forming said base layer of said print pattern by:
wherein said release liner comprises an imperforate material of a second color contrasting with said first color by a graytone interval of at least 10%, and wherein said second color is visible through said light permeable film layer.
Another embodiment of the invention comprises a method of making a vision control panel comprising:
(i) making one of the above-discussed assemblies,
(ii) applying a design to said design imaging surface of said first color to form an imaged light permeable film layer,
(iii) removing said release liner of said second color contrasting with said first color by a graytone interval of at least 10%, and
(iv) applying said imaged light permeable film layer to a transparent material.
A “vision control panel” comprises a transparent sheet and a print pattern which partially covers the transparent sheet which, together with the conditions of illumination on either side of the panel, modify the visibility from one side of the panel of objects spaced from the other side of the panel.
A “see-through graphic panel” is a vision control panel comprising a design superimposed on or forming part of the design imaging surface within the print pattern. U.S. RE37,186 discloses see-through graphic panels comprising an opaque print pattern or “silhouette pattern.” U.S. Pat. No. 6,212,805 discloses see-though graphic panels comprising a translucent design and a translucent print pattern or “base pattern.”
As one of ordinary skill in the art would appreciate, through vision can typically be obtained in either direction through a vision control panel when the level of illumination perceived through panel from the far side of the panel is high enough relative to the illumination reflected from and/or transmitted through the print pattern and any design when observed from the near side of the panel
A “light permeable material” allows the transmission of light.
In the context of this invention, the term “transparent” refers to either a transparent material or a void or voids in a film layer, for example perforation holes in a perforated film or gaps between cut film “stripes”.
A “transparent material” allows an observer on one side of the transparent material to focus on an object spaced from the other side of the transparent material. Examples of transparent materials include glass and transparent plastics, for example transparent polyester, acrylic, polycarbonate or pvc.
A “print pattern” subdivides the light permeable film layer into a plurality of discrete print areas and/or a plurality of discrete transparent areas. The print pattern also subdivides the assembly into a plurality of discrete base layer areas and/or a plurality of discrete areas devoid of a base layer. The print pattern is optionally a regular geometric element in a regular layout, such as a pattern of dots, a regular geometric element in an irregular layout, a free form element in a regular layout, a free form element in an irregular layout or a combination of regular and free-form elements in regular and/or irregular layouts. Instead of a number of separate elements with an interconnected transparent zone, the print pattern can be a pattern of separate print pattern elements, such as a pattern of lines with separate gaps between the lines. The print pattern may be formed by interconnected print pattern elements with separate transparent areas, such as a net, grid or mesh pattern, or a perforated material.
A “design” comprises a design color layer of different color to the first color of the design imaging surface. The term design is intended to include any graphic image such as indicia, a photographic image or a multi-color image of any type. The design is typically perceived to be visually independent of the elements of the print pattern both immediately after application of the design to the assembly before removal of the release liner to make a vision control panel and after removal of the release liner from the imaged assembly before applying the imaged light permeable film layer to the transparent material to form a vision control panel. This feature can be tested by an observer adjacent to one side of the imaged assembly or vision control panel from which the design is normally visible, who moves away from the one side of the panel in a perpendicular direction from the imaged assembly or vision control panel until discrete and/or interconnected elements of the print pattern can no longer be resolved by the eye of the observer, the design remaining clearly perceptible. Design imaging techniques include litho printing, screen printing and various digital imaging methods, for example inkjet printing, electrostatic transfer printing and thermal mass transfer printing or sublimation.
A “design color” can be any color of any “hue”, “saturation” and “value” or graytone (determining its darkness or lightness), including monochromatic black, white or gray, known as achromatic colors, or any metallic color such as silver or gold.
There are several different systems of color measurement and parameters for describing color including hue, saturation and value.
A “hue” is a pure color defined by a wavelength of light. “Saturation” refers to the purity of a color in relation to its gray content. Maximum saturation or “chroma” colors contain no gray.
“Value” refers to how light or dark a color is, sometimes referred to as brightness or luminance, described for the purpose of this invention as a “graytone” on a “grayscale”, which may be numerically quantified, typically from 0 (black) to 256 (white), or as a percentage from 0% (white) to 100% (black). The difference between two values of gray or graytones is known as an “interval” or a “contrast value” or herein as a “graytone interval” or a “difference in graytone”.
The term “second color” or “contrasting color” according to the present invention includes a single color or a plurality of colors with an average difference in graytone of at least 10% from the first color of the design imaging surface, though in practice an average difference in graytone of at least 30% from the first color is preferable. The term “average difference in graytone” means a weighted average, sometimes referred to as a Gaussion blur, of a non-uniform second color, for example of a mottled, streaked, halftone or bitmap appearance of a plurality of colors. The “second color” is typically a gray or plurality of achromatic colors, in order to avoid perceived modifications of the hues in the design colors, although it should be understood that a true achromatic gray is not achievable with so-called subtractive colorants such as inks, pigments, dyes and toners. There is inevitably some hue to a printed gray, however slight, and in practice a printed gray optionally comprises deposits of cyan, magenta and yellow as well as black ink on a white design imaging surface which is not truly achromatic white.
In the context of this invention, a colorless, non-pigmented transparent or translucent material is deemed to have a graytone of 0% (zero percent). For example, if the design imaging surface is transparent, any second color having a graytone of at least 10% is deemed to have a difference in graytone of at least 10% to that of the transparent “first color”. Conversely, for example, a colorless, non-pigmented transparent or translucent release liner would not provide a 10% graytone color contrast to a white design imaging surface, but would have zero percent contrast.
A cross-section can be taken through a typical assembly of the invention comprising a release liner having two outer edges, a light permeable film layer and a plurality of alternate base layer portions and portions devoid of base layer, each base layer portion comprising two outer edges. The average width between the two edges of the base layer portions is typically less than 10 mm, preferably less than 6 mm, and more preferably less than 3 mm. The average width of the portions devoid of base layer is typically less than 10 mm, preferably less than 6 mm, and more preferably less than 3 mm. Following application of the design comprising the design imaging layer, the cross-section in the same position as above comprises the base layer portions imaged by the design imaging layer, the design imaging layer optionally being applied to all or a numerically reduced plurality of said plurality of base layer portions, the design imaging layer typically not covering all of the design imaging surface of said plurality of base layer portions, the design being singular and perceived to be independent of the print pattern comprising the base layer portions, as outlined above.
In a first embodiment of the invention, a perforated film assembly comprises:
(i) a perforated film layer comprising a design imaging surface of a first color, for example a white design imaging surface of a white on black vinyl film layer or a white vinyl film layer,
(ii) a perforated adhesive layer, for example a clear or black pressure-sensitive adhesive,
(iii) a perforated release liner, for example a perforated paper liner with a silicone coating, and
(iv) an additional non-perforated backing layer of a second color contrasting with the first color of the perforated film layer, for example dark gray or black, which is adhered to the perforated release liner to form a composite release liner. The additional non-perforated backing layer acts as a background to a design applied to the perforated film layer imaging surface before removal of the composite release liner comprising the perforated liner and additional non-perforated backing layer and application of the imaged perforated film layer to a transparent material, for example a window, by means of the perforated adhesive layer, to form a see-through graphic panel. The additional non-perforated backing layer is optionally paper adhered to the perforated release liner, for example a self-adhesive paper, for example a so-called application tape, or a plastic film, for example of polypropylene, for example heat bonded to the perforated release liner. The second color is either that of the parent material of the additional non-perforated backing layer or a coating applied to it, for example the pressure-sensitive adhesive layer of a self-adhesive application tape or a colored layer printed or otherwise coated onto the non-perforated backing layer.
In a second embodiment, a perforated film assembly comprises:
(i) a perforated film comprising a design imaging surface of a first color, for example a white design imaging surface of a white on black vinyl film layer or a white vinyl film layer,
(ii) a perforated adhesive layer, for example a clear or black pressure-sensitive adhesive, and
(iii) a non-perforated release liner, for example a release-coated paper, for example a silicone-coated paper, or silicone-coated polyester film, for example a replacement liner according to U.S. Pat. No. 5,858,155, comprising a second color contrasting with the first color of the perforated film layer, for example gray or black.
In a third embodiment, a perforated film assembly comprises:
(i) a perforated film comprising a design imaging surface of a first color and having adhering properties to glass, for example a static cling film, for example comprising white-on-black highly plasticized pvc film or, for example, a urethane coated polyester film, and
(ii) a non-perforated release liner, for example a release-coated paper, for example a silicone-coated paper, comprising a second color contrasting with the first color of the perforated film layer, for example of gray or black color.
In a fourth embodiment of the invention, a cut film assembly comprises:
(i) a cut film comprising a design imaging surface of a first color, for example cut white-on-black vinyl stripes,
(ii) a cut adhesive layer, for example a cut clear or black pressure-sensitive adhesive, and
(iii) a non-perforated release liner, for example a release-coated paper, for example a silicone-coated paper, or silicone-coated polyester film, comprising a second color contrasting with the first color of the cut film layer, for example gray or black.
In a fifth embodiment, a transparent film assembly comprises;
(i) an imperforate transparent film comprising a print pattern with a design imaging surface of a first color, for example of white ink,
(ii) an adhesive layer, typically a water clear pressure-sensitive adhesive
(iii) a non-perforated release liner, for example a release-coated paper, for example a silicone-coated paper, or silicone-coated polyester film, comprising a second color contrasting with the first color of the design imaging surface of the print pattern, for example gray or black.
In one or more of these embodiments, the second color is optionally that of the parent material of the non-perforated release liner, or a coating, for example a printed colored layer, or a pigmented release coating.
In one or more of the above embodiments, the second color may contrast with the first color of the light permeable film layer by a difference in graytone of at least 10%, typically having a difference in graytone of at least 30%. Following removal of the release liner, the imaged perforated film layer is applied to the transparent material, for example the glass window of a building, vehicle, bus shelter or payphone kiosk, or a plastic sheet, for example an acrylic or polycarbonate sheet in a retail display.
Design inks, for example cyan (C), magenta (M), yellow (Y) and process black (K) are typically translucent and are typically not clearly visible against a black or dark gray colored liner providing a background to the printed design similar to the in-service condition of an imaged perforated material applied to the window of a relatively dark interior of a building or vehicle.
Various embodiments of the invention include many alternatives and variants to the above embodiments. On example perforated film assembly with a dark contrasting color liner comprises a pre-perforated facestock film and discrete areas of clear pressure-sensitive adhesive on a non-perforated, contrasting color liner. As another example, a perforated film assembly comprises an imperforate, clear supporting film layer, for example a polyester film, laminated to a pre-perforated facestock film, for example a white on black film laminate, a non-perforated layer of clear pressure-sensitive adhesive and a non-perforated, contrasting colored liner.
The non-perforated component of the contrasting color liner optionally comprises an absorbent material, for example a non-sealed black paper, for example adhered to the perforated liner of the first embodiment, for example by means of a heat-activated adhesive coated on the side of the perforated liner remote from the perforated adhesive layer. The imperforate material optionally comprises a recycled paper, for example comprising a grain effect which is optionally preferred to a uniform gray contrasting color. Similarly, the release liner optionally comprises a multi-color effect or coating, for example black printed in a fine pattern on the imperforate material, for example a fine halftone or an irregular mottled, streaked or bitmap pattern. Optionally, the contrasting colored non-perforated liner comprises activated carbon particles acting as a pigment to provide the required color, for example black or gray, which will also absorb solvent and reduce odours from colorants, for example the smell of solvents emitted from solvent inks.
For the first three above-discussed embodiments, a perforated film assembly comprising a contrasting color liner typically presents an array of contrasting colored substantially circular apertures visible to an optical scanning device incorporated into a printing machine, for example an inkjet printing machine. Such systems can gather data from a loaded self-adhesive assembly sheet or roll to:
(i) acquire the size of any perforation anywhere on the loaded sheet or roll;
(ii) acquire the number of perforations per any unit of linear or area measure;
(iii) calculate the precise ratio of material to void;
(iv) ascertain the orientation of a loaded sheet of material;
(v) search for and verify the position and/or presence of a “distinguishing hole” or other distinguishing non-hole feature, for example as a device to distinguish from licensed and infringing products;
(vi) modify the jetting of the image such that ink is substantially prevented from being deposited into voids;
(vii) modify the jetting of the image such that the image intensity and contrast characteristics suit the balance of void to material;
(viii) use the presence of a distinguishing hole to trigger a unique code, symbol, text or logo to be jetted with the image data upon the sheet;
(ix) use the presence of the holes to calculate the extent of the area available as useful imaging area and its orientation;
(x) position the jetted image upon the sheet in such a manner that digital artifacts arising from the visual interaction of void and image areas are avoided or minimized, for example to avoid Moiré fringe effects;
(xi) create and execute a cut path co-extensive with imaged areas and, wherever possible, such that the cut path avoids cutting across voids so optimizing the structural integrity of the sheet; and/or
(xii) calculate the extent and amount of tension-induced distortions in the presented array of holes and distort the jetted image, for example so as to compensate when the tension-induced distortion is relieved.
Similar data and benefits can be derived from the cut film or printed print patterns of the fourth and fifth embodiments.
A feature of one or more embodiments of the present invention is that a printer can be confident in the application of less ink to the assembly, where appropriate, than would have been the case with prior art assemblies. Other features of one or more embodiments of the present invention include reduced time of printing for certain types of printing, such as inkjet printing, and less cost of ink. Another feature of one or more embodiments of the present invention is a reduction of the dwell time or elapsed time of any ink curing, as there is typically less ink deposited on the design imaging surface and, with solvent inks, a reduction in the wet to wet interaction of successive ink deposits. Environmental features according to one or more embodiments of the present invention include less VOCs (Volatile Organic Compounds), for example in ink solvents, emitted into the atmosphere.
If prior art perforated or cut film assemblies are inkjet printed, the ink is typically applied to both the print pattern and void areas.
One or more of the first four embodiments may enable selective printing of the perforated or cut film layer with reduced or no ink deposition in the void positions, for example by image recognition systems, for example comprising a camera located ahead of an inkjet printhead array in an inkjet printing machine. Such camera recognition systems can also be used in the fifth embodiment, for example to selectively apply design ink onto a white design imaging surface of a print pattern.
Photographic imaging techniques can be used to print the design, for example on a perforated or cut film light sensitive film, for example by known photographic negative or transparency or digital laser imaging machines, for example as supplied by Durst or Raster Graphics. A black contrasting liner may benefit the photographic imaging process as it absorbs light rather than scattering light back to the imaging hardware or around the void areas where it could cause undesirable image artifacts. In photographic imaging, the contrasting colored liner preferably does not absorb liquids because of the subsequent development process. The release liner optionally comprises “anti-halation” treatments known in the photographic art.
A potential disadvantage with various prior art UV inkjet imaging of a perforated film layer is that ink applied within the holes can acquire sufficient membrane or “in-plane” strength, owing to the chemical cross-linking of UV curing, to be removed with the facestock on removal of the liner. With a gray or black release liner according to one or more embodiments of the present invention, the speed of curing of unwanted ink on the gray or black liner may be reduced, compared to a white or otherwise reflective liner, because a higher proportion of UV rays are absorbed rather than being reflected back through the ink. This greater absorption may tend to reduce the membrane or in-plane strength of the ink within the perforation holes, causing it to be removed with the liner, as desired.
Techniques of undercolor removal can advantageously be used in conjunction with various contrasting colored liners, to help achieve the desired visual effects in the finished product, for example after application to a window, in conjunction with the further saving of ink that undercover removal techniques provide.
Theoretically, the provision of gray areas (as with the prior art white areas) may provide the opportunity for the phenomenon of “simultaneous contrast” in which colors contrasting to the adjacent printed colours could be seen on the gray portions, but the fineness of the printed portions and the gaps between the printed portions, would appear to render this potential effect non-discernible to the naked eye.
Instruments, for example a spectrophotometer, can be used to analyze color and, in the case of the present invention, enable the manipulation of color in a design in order to achieve the desired effect in-situ, typically on a window of a building or vehicle. The contrasting color of the liner will typically be within the range from a neutral or achromatic graytone of 30% to black, preferably 50% to black, and possibly more preferably 70% to black according to various embodiments. If the principal intention of an embodiment of the invention is to improve the perception of the imaged assembly to a print operative, for example to avoid excessive application of ink, the selected graytone will typically be in the range of 60% to 80%. The visual impact or strength of a design is in part determined by contrast in colors, their juxtaposition and their respective proportional areas. A spectrophotometer can be calibrated and adjusted to determine the desirable adjustment, typically of color “value”, otherwise referred to as graytone and brightness, together with any undercolor removal, in order to achieve the desired effect for a particular project. Color hues will not typically be varied, although there are various techniques known in the art which may be used, for example adding blue to white to result in an apparently increased brightness of the white.
One basis of determining a commercially practical and desirable background graytone is to consider the visual perception of the imaged self-adhesive assembly compared to a conventionally printed ‘standard’ image on a white uniform background. Tests were undertaken according to conventional visual perception test methodologies using five naïve participants. The participants observed a total of ten options including:
(i) 8 different backgrounds of a minimum variance of 5% graytone under a printed image on a perforated base material facestock applied to a clear substrate, together with
(ii) a printed prior art assembly with the same image on the same type of facestock with a prior art white liner on which solvent inkjet ink had coalesced to cover only a small proportion of each hole area, and a
(iii) a printed prior art assembly with the same image on the same type of facestock with a dark graytone liner of the present invention assessed to be approximately 90% graytone, on which solvent inkjet ink had coalesced to cover only a small proportion of each hole area.
All the participants were asked to:
(i) grade the ten options with different background graytones marked with random letters in order of perceived lightness to darkness,
(ii) identify which of the randomly lettered samples appeared most like a “standard” version of the image printed on a white unperforated substrate, and
(iii) “mark” the likenesses of the prior art imaged sample and the selected option of (ii) on a scale of 20 compared to the “standard” image awarded 20 points and the black, 100% graytone background awarded 10 points.
All participants correctly graded all ten options, including five from 60% to 80% graytone having intervals of 5% graytone. This result is unsurprising given the human brain's known ability to distinguish between hundreds of thousands of different colors. All participants selected the same option as being most like the particular standard image. The marks of likeness of the prior art imaged sample compared to the standard image ranged from 1 to 4, average 2.8, and the likeness marks of the selected option (ii) ranged from 10 to 14, average 12.2, representing a clear indication of the benefits of various embodiments of the invention. This test program also indicated that a graytone background of 30% graytone was considered preferable to the prior art white background and any graytone background within the range of 30% to 100% was considered preferable to the prior art construction with the selected image.
To optimise a particular graytone for a range of images is theoretically possible and complex but in practice has been found not to be critical. To consider the desired likeness of a printed self-adhesive assembly to a “standard” rendering of an image on a solid white background, in order to:
(A) deter print operatives from applying too much ink, and
(B) to achieve customer satisfaction on delivery of a printed self-adhesive assembly, a number of selected, representative images in a particular field of commercial advertisements were converted to achromatic or graytone images by a methodology commonplace in the graphic arts. These were processed by prior art methods to produce a weighted average graytone for each image, their percentage values being assessed against samples of graytone with intervals of 5%. An average background graytone was then determined for this range of images by calculating the simple arithmetic average of the weighted averages of graytone of the selected images, being approximately 70%.
Another basis for deciding on a commercially desirable background graytone would be to consider
(C) the likely darkness of the typical background interiors to the windows on which the imaged self-adhesive films are to be applied, in order that the printed self-adhesive assemblies can be assessed against their appearance following application to a window. The darkness of interiors is dependent upon many factors, including their spatial size, the area and configuration of all windows, any glazed partitions and doors which allow daylight or external artificial light to enter the space, any internal artificial lighting and the colors, textures and consequent reflectance of the interior surfaces. In certain conditions, the interior could be brighter than the exterior. Specific conclusions can be arrived at for particular markets, for example for imaged perforated base materials to be applied to bus windows, but it is felt that criteria (A) and (B) are typically the most important in determining a generally desirable and applicable contrasting color for a liner. A conclusion of the tests was that a second color (including the option of a multi-color second color) of an achromatic graytone (or average graytone) within the range of 60-80% is generally compatible with a wide range of commercial graphic images but that any achromatic graytone second color in the range of 30-100% is beneficial. A fine, irregular, multi-colored achromatic “second color” for the imperforate material of the release liner has been found to be particularly advantageous according to one or more embodiments in reducing the impact of the negative pattern of the print pattern on the perceived design 14.
Additional and/or alternative objects, features, aspects, and advantages of the present invention will become apparent from the following description, the accompanying drawings, and the appended claims.
For a better understanding of embodiments of the present invention as well as other objects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, where:
The replacement release liner 9 is optionally self-colored, for example a black or gray sheet of paper with a substantially clear silicone release coating or, as illustrated in
It is possible with one or more of the above embodiments and many more embodiments to arrange that an “engineered substrate” is formed comprising a light permeable film layer, a print pattern comprising a plurality of discrete base layer areas and/or a plurality of discrete areas devoid of the base layer, the base layer comprising a design imaging surface of a first color, and a release liner comprising an imperforate material of a second color contrasting with the first color by a graytone interval of at least 10%, the second color being visible through the light permeable film layer. Such engineered substrates are optionally mass produced for sale to printers for application of the design comprising a design color layer to form an imaged light permeable film layer, whereupon the second color of the imperforate material typically remains visible through the light permeable film layer, the imperforate material being imaged or the second color being visible in combination with and optionally amended by the design color layer or design color layers which are typically translucent. The design is visible in conjunction with the revealed second color and/or amended second color in the transparent portions of the light permeable film layer.
In addition to the previously mentioned benefits of one or more embodiments, an imaged assembly provides an advantageous way of demonstrating to potential customers of see-through graphic panels how the product would work in situ. A full image printed on a solid white background gives a false impression of the achievable quality in a see-through in situ, which necessarily is not as good as a full image and may unduly raise expectations leading to subsequent dissatisfaction, whereas a prior art sample with a white release liner gives a very poor impression of the achievable quality in situ, almost certainly causing the loss of a proportion of sales as a result. Imaged assemblies of one or more embodiments of the present invention will assist the realistic demonstration of the potential quality of see-through graphics, for example on the windows of buildings and vehicles, and thus assist sales.
The foregoing illustrated embodiments are provided to illustrate the structural and functional principles of the present invention and are not intended to be limiting. To the contrary, the principles of the present invention are intended to encompass any and all changes, alterations and/or substitutions within the spirit and scope of the following claims.
This application claims the benefit of priority to U.S. Provisional Patent Application No. 60/941,882, titled “Vision Control Panel Assembly With A Contrasting Liner,” filed on Jun. 4, 2007, which is incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB08/52189 | 6/4/2008 | WO | 00 | 1/26/2010 |
| Number | Date | Country | |
|---|---|---|---|
| 60941882 | Jun 2007 | US |
