WO2016035093A1

WO2016035093A1 - Process of providing fresnel lens on fibrous substrate for packaging and other applications and substrate made thereof

Info

Publication number: WO2016035093A1
Application number: PCT/IN2015/000315
Authority: WO
Inventors: Ashok Chaturvedi
Original assignee: Ashok Chaturvedi
Priority date: 2014-09-01
Filing date: 2015-08-06
Publication date: 2016-03-10
Also published as: WO2016035093A8; IN2014DE02473A

Abstract

A fibrous or fabric substrate having Fresnel lenses obtained from a process comprising coating the substrate with a radiation curable coating; embossing the curable coating with a Fresnel lens master; and curing the curable coating using UV or E-beam radiation followed by metallization. The invention also provides a process for providing at least one metalized Fresnel lens on a fibrous or fabric substrate by hot or cold foil stamping.

Description

PROCESS FOR PROVIDING FRESNEL LENSES ON A SUBSTRATE FOR PACKAGING AND OTHER APPLICATIONS AND A SUBSTRATE MADE THEREOF.

FIELD OF THE PRESENT INVENTION

The invention generally relates to substrates for packaging and other applications and more particularly to fibrous or fabric substrates having Fresnel lens.

BACKGROUND

In today's competitive consumer market, decorative packaging has become very important and is used as a marketing tool to attract the attention of potential shoppers. It is known in the art to create or transfer Fresnel lenses on a film and metalize or back the film with a light reflecting surface. Such Fresnel lens films are known to be used for packaging to make them more attractive.

It is also known in the art to laminate such films with Fresnel lens to other substrates such as paper, paperboards in order to achieve Fresnel lens on packaging cartons, boxes, Bags & Sachets etc. Subsequently, surface printing needs to be done on the laminate over the outer surface of the film. This surface printing is prone to wear and tear and is not rub- resistant.

Further, it is desired and well known in the art to configure such Fresnel lenses by lamination with the film having Fresnel lens to another substrate such as another polymeric film, or fibrous substrates such as paper, or paper board, synthetic fibrous substrates, etc.

It is also desired that it should be possible to incorporate Fresnel lenses with other substrates such as fabric, textile, and the like. Fresnel lenses on substrates such as textile can be used as a unique packaging substrate or the cloth so obtained may be used to manufacture apparels such as fancy dresses. However, due to technical limitation of the process of creation / transfer of Fresnel lenses, incorporation of Fresnel lenses with substrates such as textile has not been possible. Further, it has been observed that the known methods of incorporating Fresnel lenses on various substrates as listed above are complex and expensive.

Also, the instances of printing over the Fresnel lenses have been spoiling the look of the lens such that any portion of a Fresnel lens which is printed upon is obscured by the printing process.

It is desirable that the method of applying Fresnel lenses on substrates such as paper or paper board should be simpler, efficient, and cost-effective, allowing easier further processing. It is also desirable to provide an image or text as security feature to ensure originality of the product, over the Fresnel lens without obscuring the lens. It is also desired that the process should be simple so as to enable creation / transfer of Fresnel lenses on substrates such as textile.

While incorporating Fresnel lenses over substrates using hot or cold stamping process known in the art, it has been observed that the edges on the periphery of the Fresnel lenses so incorporated appear to be broken, torn or having burrs and don't look sharp. Further, it is desired that the Fresnel lenses are incorporated in the form of a pattern or an array of small Fresnel lenses. The small Fresnel lenses in the array may be circular, triangular, star - shaped or any other geometrical shape or pattern.

Therefore, there is a need for providing a method for making a decorative / fancy substrate with Fresnel lens, increasing the aesthetic value of the packaging / apparel which obviates the disadvantages of the prior art. Also, it should be possible to use the substrate for various applications such as wall papers, floor coverings, apparels, etc. and incorporate an effective security / anti-counterfeit feature in addition to the Fresnel lens without compromising on the appearance of the lens when viewed through a naked eye. SUMMARY OF THE PRESENT INVENTION

Accordingly the present invention provides a process for providing Fresnel lenses on a substrate comprising the steps of coating the substrate with a curable coating, the curable coating being capable of curing using a radiation; embossing the curable coating with a Fresnel lens master, the Fresnel lens master imparting a pattern on the curable coating; and curing the curable coating using the radiation.

In another aspect the invention provides a process for providing at least one metalized Fresnel lens on a substrate by hot or cold foil stamping using a stamping punch and a stamping foil, wherein the size of the stamping punch is more than the size of the Fresnel lens.

The invention also provides a fibrous or fabric substrate having Fresnel lenses with sharp edges prepared by a process comprising the steps of coating the substrate with a curable coating, the curable coating being capable of curing using a radiation; embossing the curable coating with a Fresnel lens master, the Fresnel lens master imparting a pattern on the curable coating; and curing the curable coating using the radiation.

In yet another aspect, the invention provides a fibrous or fabric substrate having at least one Fresnel lens prepared by a process of hot or cold foil stamping comprising providing a stamping foil and a stamping punch having size more than the size of the Fresnel lens thereby ensuring sharp edges of the Fresnel lens.

These together with the other aspects of the invention, along with the various features of novelty that characterize the invention, are pointed out with particularity in the description, along with the abovementioned summary, annexed hereto and form a part of the invention. For a better understanding of the invention, its operating advantages and the specified object attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart depicting a process of making a Fresnel lens over a substrate, in accordance with an embodiment of the invention.

FIG. 1 A is a flowchart depicting a process of making a substrate with Fresnel lens, in accordance with another embodiment of the invention.

FIG. 2A illustrates the process of incorporating a Fresnel lens on the substrate by coating, embossing & curing, in accordance with an embodiment of the invention.

FIG. 2B illustrates the process of incorporating a Fresnel lens on the substrate by hot or cold stamping, in accordance with an embodiment of the invention.

FIG. 3 illustrates a cross sectional view and top view of a substrate having a metalized Fresnel lens, in accordance with an embodiment of the invention.

FIG. 4A & 4B illustrates a process of transferring a latent image on

Fresnel lens, in accordance with an embodiment of the invention.

FIG. 5 illustrates a process of laminating a reverse printed polymeric film with the substrate having a metalized Fresnel lens, in accordance with an embodiment of the invention.

Figs. 6A-E illustrates various exemplary embodiments for providing the Fresnel lenses on roll of substrate and cut piece of substrate roll in accordance with an embodiment of the present invention.

Like reference numerals refer to like parts throughout the description of several views of the drawings.

DESCRIPTION OF THE PRESENT INVENTION

For a thorough understanding of the invention, reference is to be made to the following detailed description in connection with the above- mentioned drawings. Although the invention is described in connection with embodiments, the invention is not intended to be limited to the specific forms set forth herein. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but these are intended to cover the application or implementation without departing from the spirit or scope of the invention. Further, it will nevertheless be understood that no limitation in the scope of the invention is thereby intended, such alterations and further modifications in the figures and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Further, reference herein to "one embodiment" or "an embodiment" means that a particular feature, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. Furthermore, the appearances of such phrase at various places herein are not necessarily all referring to the same embodiment. The terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

Various embodiments of the present invention provide a process for incorporating Fresnel lenses on a substrate. In another aspect, the invention also provides a substrate having a Fresnel lens made from such process.

FIG. 1 is flow chart depicting process (100) for providing Fresnel lenses on a substrate (220) (shown in FIG. 2A and 2B), in accordance with an embodiment of the invention. At step (102), the substrate (220) is selectively coated with a UV curable or E-beam curable coating (214) at locations where Fresnel lenses are required. It may also be contemplated that the coating with curable coating (214) may be performed all over the surface of the substrate (220). This coating (214) (shown in FIG. 2A) is provided either registered or unregistered with respect to a mark / printed matter on the substrate (220). The registration mark may be an eye mark, perforation, text, logo and the like on the substrate (220). For example, as shown in FIG. 3, Fresnel lenses (212) are registered with respect to an eye mark (310). However, in embodiments where the substrate (220) is plain and unprinted, the registration mark may also be printed at step (102) along with coating for Fresnel lens embossing. The said registration mark is subsequently used for the registration of embossing, printing, punching, holography, lamination with other substrates / film & other related processes.

At step 104, the coating (214) layer is embossed with a Fresnel lens master (240). In an embodiment, the embossing is performed either registered or unregistered with respect to a mark / printed matter on the substrate.

A single Fresnel lens is generated by machining on a metallic surface such as Steel, Copper, Nickel, Aluminum and the like or hard plastic such as Poly Carbonate and the like, using highly precise Computer Numerical Control (CNC) Machine.

As per requirement, the single Fresnel lens so generated is recombined either manually or by UV recombining machine to form multiple embossed images on PET, PVC or Polycarbonate film. This parent master film can be used in various ways to configure Fresnel lens on substrate with curable coating (214):

i. by electroplating / electroforming of metal such as Nickel, on the surface of the parent master film, a metal master is obtained which is used to emboss polymer film to produce Fresnel lens master (240).

ii. The parent master film can be assembled on a cylinder and can be used for Fresnel lens embossing on the coated substrate but this is not economical.

iii. The parent master film so obtained is used to transfer the Fresnel lens embossing on to a cylinder through a UV curable coating method. One such method has been disclosed in patent application no. 4006/DEL/2012 titled "Method of making holographic embossing cylinder and apparatus for embossing hologram using holographic embossing cylinder on flexible packaging substrate". The thickness of the coating on the surface of the cylinder depends upon the parameters of the lens desired.

Depending upon the process selected from the above, the image on the single Fresnel lens master may be negative or positive to obtain Fresnel lenses of desired generation (+ve/-ve) on the substrate (220).

In an embodiment, a cylinder (230) carrying the Fresnel lens master (240) transfers the embossed image on the curable layer (coating 214) of about 5 ~ 350 microns on the substrate (220), as illustrated in FIG. 2A. It may be apparent that a single Fresnel lens or a pattern of Fresnel lenses may be registered or unregistered applied to the substrate, using a Fresnel lens master (240) prepared accordingly. The said pattern of Fresnel lenses on a roll of substrate may include:

(a) a predetermined row of the Fresnel lenses wherein the Fresnel lenses are located at predefined locations on the substrate from roll of substrate. The locations of the Fresnel lenses in row are shown in figure 6A as an exemplary embodiment of the present invention. In another embodiment, the number of rows and distance between the Fresnel lenses may be provided as per the requirement of user;

(b) a predetermined array of the Fresnel lenses wherein the Fresnel lenses are located at predefined locations on the substrate from roll of substrate. The array of the Fresnel lenses is shown in figure 6B as an exemplary embodiment of the present invention; and (c) a group or cluster of the Fresnel lenses. The said group or cluster may comprise a predetermined number of the Fresnel lenses and predefined shape and size of the Fresnel lenses. The shape or the size of one or more Fresnel lenses provided in the group or cluster may be identical or different from one another. In an embodiment, the group or cluster may also comprises one or more Fresnel lenses wherein the Fresnel lens may be a complete Fresnel lens or randomly cut portion(s) of Fresnel lenses or a combination thereof. The group or cluster may be located at predetermined locations on the substrate roll. The group or cluster of Fresnel lenses on the substrate roll is shown in figure 6C as an exemplary embodiment of the present invention.

Further, in case of cut pieces of a substrate roll, the pattern of the Fresnel lenses may include: (a) a predetermined array of the Fresnel lenses wherein the said

Fresnel lenses are provided at predefined locations on the cut pieces of substrate. The array of the Fresnel lenses on the cut piece of substrate is shown in figure 6D as an exemplary embodiment of the present invention; and (b) a group or cluster of the Fresnel lenses. The said group or cluster may comprise a predetermined number of the Fresnel lenses and predefined shape and size of the Fresnel lenses. The shape and / or the size of one or more Fresnel lenses provided in the group or cluster may be identical or different from one another. In an embodiment, the group or cluster may also comprises one or more Fresnel lenses wherein the Fresnel lens may be a complete Fresnel lens or randomly cut portion(s) of Fresnel lenses or a combination thereof. The group or cluster may be located at predetermined locations on the cut pieces of substrate. The group or cluster of Fresnel lenses on the cut piece of substrate is shown in figure 6E as an exemplary embodiment of the present invention.

S At step (106), the embossed curable layer is cured using UV or E- beam. Curing the coating may be performed using one of:

a. UV: can only be done from the side of coating if the substrate is translucent or opaque or b. E-beam: may be done from either side of the substrate of any type

At step (108), the embossed and cured surface of the substrate (220) is metalized with a metallic layer either selectively over the embossed and cured Fresnel lenses or over full surface of the substrate (220) to get a mirror-like lens effect. The metallic layer includes any of Aluminum, Aluminum Oxide, Zinc Sulphide, Silicon Oxide, Silver, Gold, Copper, Chrome, Silicon Monoxide, Silicon Dioxide, Magnesium Fluoride, Titanium Dioxide, Tin Tungsten Oxide and Indium Tin Oxide or any other suitable metal, or their combination. Optionally, metalizing may be performed either:

a. Selectively at desired locations and preferably over the Fresnel lenses. For example, metallization (212m) on Fresnel lenses (212) is shown in enlarged cross- sectional view of FIG. 3. The top view shows the three metalized Fresnel lenses (212) on substrate (220) or b. All over the surface of the substrate (220) including embossed Fresnel lenses but excluding any registration mark, if present.

In an embodiment, process (100) includes the step of providing a protective lacquer coat over the metallization provided at step 108.

In an alternate embodiment, the step (102A) is performed instead of step (102) to step (108). This alternate embodiment has been shown as process (100A) in the form of another flowchart in FIG. 1A. At step (102A), at least one or more metalized Fresnel lenses (212B) are hot or cold foil stamped using a punch (250) and hot or cold stamping foil (260), registered or unregistered, on the substrate (220) such as textile, coated / uncoated paper or paper board as shown in FIG. 2B. The Fresnel lens stamping may be performed on a roll of substrate web or cut pieces of substrate, on flat bed stamping machine having single / multiple stamping punches or by a stamping roller having single / multiple stamping punches, duly registered or unregistered. The stamping machines used for stamping may or may not have foil saving systems.

In an embodiment, as shown in FIG.2B, a periphery of a stamping punch lies outside a periphery of the Fresnel lens, i.e., the size of the stamping punch (250) is more than the size of the lens (212B) and preferably only marginally more than the lens (212B) so that the detachment from stamping foil (260) during stamping happens outside the lens periphery. Bigger size of punch (250) also provides wider registration tolerances during stamping. Metallization at step (108), if done selectively, is done on the surface of the substrate (220) at least up to or beyond the periphery of the Fresnel lens (212B). The bigger size of the punch than the Fresnel lens ensures that the tearing happens outside the embossed Fresnel lens when the stamping foil (260) is peeled off the substrate after stamping ensuring that the problem of broken edges of the stamped lens. The broken edges or burrs on the edges appear when the stamping punch edges fall over the embossed circular rings of the Fresnel lens and the tearing happens somewhere over the rings.

Subsequently, steps (1 10-116) of process (100) and (100A) are similar and for the sake of brevity description with reference to only process (100) is provided.

In an embodiment of the invention at step (110), to provide an effective security / anti-counterfeit feature, in addition to the Fresnel lens, optionally a latent image / text is configured over the Fresnel lens. This latent image is not visible to a naked eye and only visible under special conditions such as under specified light (UV), using a polarizer, viewing at certain angle, on application of some chemical or steam / moisture and the like. To configure the latent image, a layer of 2-15 micron coating of a release coating such as wax or Silicon or synthetic natural oil or polymer based which is transparent, is applied to one surface of a flexible polymeric film (410) (FIG. 4A) such as Polyethylene Terephthalate (PET), Biaxially Oriented Polypropylene (BOPP), Polyvinyl Chloride (PVC), Nylon, Polycarbonate (PC), or any plastic film of 5 to 100 microns. A latent image (412) in the form of a thin transparent layer is configured over the release coating on the surface of the flexible polymeric film (410). A transparent thin layer of suitable adhesive is applied over the latent image (412). The latent image (412) may be any text, alphanumeric character or a picture or pattern or a combination of these, etc. For example, as shown in FIG.4B, the latent image (412) is text.

The flexible polymeric film (410) with latent image (412) and a layer of adhesive, so obtained is laminated with the substrate (220), as shown in FIG. 4A. The laminate may then be cured for a specified period of time. Subsequently, the flexible polymeric film (410) is removed / peeled-off, as shown in FIG. 4A and the latent image (412) configured thereon is transferred over the Fresnel lens (212) on the substrate (220).

The latent image (412) transferred over the substrate may or may not be registered with any printing or marking. FIG. 4B illustrates that the latent image (412) is visible only through a special device such as a circular polarizer (420).

Optionally, the latent image may also be provided using printing with ink visible in UV light / or holography.

In an embodiment, the process (100) optionally includes providing printing on the substrate (220). At step (112), substrate (220) is optionally printed leaving Fresnel lenses. Printing may be performed by Screen printing, rotogravure printing, offset printing, Flexographic, Digital printing and the like.

In an embodiment, at step (114), a reverse printed polymeric film / laminate is laminated with the substrate. FIG. 5 illustrates a process of laminating a reverse printed polymeric film (510) with the substrate (220) having metalized Fresnel lenses (212), in accordance with an embodiment of the invention. Film (510) has opaque printed areas (520) and unprinted transparent areas (512), which are registered with the Fresnel lens (212) on the substrate (220) while laminating, through which the lenses remain visible.

In an embodiment, at step (116), optionally the substrate is laminated with polymeric film / laminate and surface printing is performed over the outside surface of the film. Further, subsequently, optionally UV or E-beam curable coating is applied on selective or full surface of the substrate to protect and impart gloss to the surface printing.

In various embodiments of the invention, the substrate (220) may be a fibrous substrate such as coated or uncoated paper or paper board, synthetic fibrous substrates and the like, and textile, fabric or cloth and the like.

The method steps of process (100) and (100A) have been described sequentially above. However, it should be appreciated that sequence of the steps of process (100) and (100A) can be changed if required and possible.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof.

Claims

1. A process (100) for providing Fresnel lenses on a substrate, the process comprising the steps of: a. coating the substrate with a curable coating, the curable coating being capable of curing using a radiation; b. embossing the curable coating with a Fresnel lens master, the Fresnel lens master imparting a pattern on the curable coating; c. curing the curable coating using the radiation; and d. metalizing the embossed Fresnel lens at least up to the periphery of the Fresnel lens.

2. The process as claimed in claim 1 , wherein the radiation used is Ultra Violet (UV) radiation and the curable coating is capable of being cured using the Ultra Violet (UV) radiation.

3. The process as claimed in claim 1 , wherein the radiation used is E- beam and the curable coating is capable of being cured using the E-beam radiation.

4. The process as claimed in claim 1 , wherein a selective surface of the substrate is coated with the curable coating.

5. The process as claimed in claim 1 , wherein the coating is performed either registered or unregistered with respect to a mark / printed matter on the substrate.

6. The process as claimed in claim 1 , wherein the embossing is performed either registered or unregistered with respect to a mark / printed matter on the substrate.

7. The process as claimed in claim 1 , wherein the pattern imparted by Fresnel lens master comprises a single Fresnel lens, randomly cut portion(s) of one or more Fresnel lenses, a predetermined array of Fresnel lenses, a group of Fresnel lenses or a combination thereof.

8. The process as claimed in claim 1 , wherein the pattern is imparted either registered or unregistered with respect to a mark / printed matter on the substrate.

9. The process as claimed in claim 1 , wherein metallization over the embossed Fresnel lens is performed using a substance which is one chosen from the group consisting of Aluminum, Aluminum Oxide, Zinc Sulphide, Silicon Oxide, Silver, Gold, Copper, Chrome, Silicon Monoxide, Silicon Dioxide, Magnesium Fluoride, Titanium Dioxide, Tin Tungsten Oxide and Indium Tin Oxide.

10. The process as claimed in claim 1 , wherein the metallization is performed at only some selective portions of the surface of the substrate.

11. The process as claimed in claim 1 , further comprising the step of providing a protective lacquer coat over the metallization.

12. The process as claimed in claim 1 further comprising providing a latent image over the surface of the Fresnel lens.

13. The process as claimed in claim 12, wherein the latent image is provided registered or unregistered with respect to a mark / printed matter on the substrate.

14. The process as claimed in claim 1 further comprising providing printing on the surface of the substrate.

15. The process as claimed in claim 13, wherein printing is provided using a method which is one chosen from a group consisting of Screen printing, rotogravure printing, offset printing, flexographic printing, and digital printing.

16. The process as claimed in claim 1 , further comprising laminating a reverse printed polymeric film / laminate to the substrate, the reverse printed polymeric film / laminate having unprinted transparent areas.

17. The process as claimed in claim 16, wherein the lamination is performed registered with respect to the Fresnel lens / a mark / a printed matter on the substrate, enabling visibility of the Fresnel lenses through the unprinted transparent areas on the reverse printed polymeric film / laminate.

18. The process as claimed in any of the claims 1-17, wherein the substrate is fibrous.

19. The process as claimed in claim 8, wherein the substrate is coated or uncoated paper / paperboard.

20. The process as claimed in any of the claims 1-17, wherein the substrate is a fabric.

21. A process (100A) for providing at least one metalized Fresnel lens on a substrate by hot or cold foil stamping.

22. The process as claimed in claim 21 , wherein a periphery of a stamping punch lies outside a periphery of the Fresnel lens.

23. The process as claimed in claim 21 , wherein the metallization on the Fresnel lens is provided at least up to the periphery of the Fresnel lens.

24. The process as claimed in claim 21 , wherein the stamping is performed unregistered or registered with respect to a mark / printed matter on the substrate.

25. The process as claimed in claim 21 , wherein the Fresnel lenses are provided by stamping in a pattern comprising of a single Fresnel lens, randomly cut portion(s) of one or more Fresnel lenses, a predetermined array of Fresnel lenses, a group of Fresnel lenses or a combination thereof.

26. The process as claimed in claim 25, wherein the pattern is provided either registered or unregistered with respect to a mark / printed matter on the substrate.

27. The process as claimed in claim 21 , wherein the metallization over the embossed Fresnel lens is performed using a substance which is one chosen from the group consisting of Aluminum, Aluminum Oxide, Zinc Sulphide, Silicon Oxide, Silver, Gold, Copper, Chrome, Silicon Monoxide, Silicon Dioxide, Magnesium Fluoride, Titanium Dioxide, Tin Tungsten Oxide and Indium Tin Oxide.

28. The process as claimed in claim 21 further comprising providing a latent image over the surface of the Fresnel lens.

29. The process as claimed in claim 28, wherein the latent image is provided unregistered or registered with respect to a mark / printed matter on the substrate.

30. The process as claimed in claim 21 further comprising providing printing on the surface of the substrate.

31. The process as claimed in claim 30, wherein the printing is provided using a method which is one chosen from a group consisting of Screen printing, rotogravure printing, offset printing, flexographic printing, and digital printing.

32. The process as claimed in claim 21 , further comprising laminating a reverse printed polymeric film / laminate to the substrate, the reverse printed polymeric film / laminate having unprinted transparent areas.

33. The process as claimed in claim 32, wherein the lamination is performed registered with respect to the Fresnel lens / a mark / a printed matter on the substrate, enabling visibility of the Fresnel lenses through the unprinted transparent areas on the reverse printed polymeric film / laminate.

34. The process as claimed in any of the claims 21-33, wherein the substrate is a fibrous substrate.

35. The process as claimed in claim 34, wherein the substrate is coated or uncoated paper / paperboard.

36. The process as claimed in any of the claims 21-33, wherein the substrate is a fabric.

37. A fibrous substrate having Fresnel lenses prepared by a process comprising the steps of: a. coating the substrate with a curable coating, the curable coating being capable of curing using a radiation; b. embossing the curable coating with a Fresnel lens master, the Fresnel lens master imparting a pattern on the curable coating; c. curing the curable coating using the radiation; and d. metalizing the embossed Fresnel lens at least up to the periphery of the Fresnel lens.

38. A fabric substrate having Fresnel lenses prepared by a process comprising the steps of: a. coating the substrate with a curable coating, the curable coating being capable of curing using a radiation; b. embossing the curable coating with a Fresnel lens master, the Fresnel lens master imparting a pattern on the curable coating; c. curing the curable coating using the radiation; and d. metalizing the embossed Fresnel lens at least up to the periphery of the Fresnel lens.

39. A fibrous substrate having at least one Fresnel lens configured by a process of hot or cold foil stamping, the process comprising providing a stamping foil having Fresnel lenses and a stamping punch.

40. A fibrous substrate as claimed in claim 39, wherein a periphery of the stamping punch lies outside a periphery of the Fresnel lens.

41. A fabric substrate having Fresnel lenses configured by a process of hot or cold foil stamping, the process comprising providing a stamping foil having Fresnel lenses and a stamping punch.

42. A fabric substrate as claimed in claim 41 , wherein a periphery of the stamping punch lies outside a periphery of the Fresnel lens.

43. The substrate as claimed in claims 37-38, wherein the pattern imparted by Fresnel lens master comprises a single Fresnel lens, randomly cut portion(s) of one or more Fresnel lenses, a predetermined array of Fresnel lenses, a group of Fresnel lenses or a combination thereof.

44. The substrate as claimed in claim 43, wherein the pattern is provided unregistered or registered with respect to a mark / printed matter on the substrate.