A packaging film with positioning holographic effect and its preparation method and application

Abstract

The application provides a packaging film with positioning holographic effect and a preparation method and application thereof. The packaging film comprises a base film, a laser holographic layer, a graphic layer and a reflection layer which are arranged in a stack; the preparation method comprises the following steps: coating laser mold pressing information paint on one side of the base film, drying, using a mold pressing and printing all-in-one machine to press and print the graphic coating on the side of the laser holographic layer away from the base film after laser holographic pressing, forming the laser holographic layer and the graphic layer on one side of the base film; then preparing the reflection layer on the side of the graphic layer away from the base film to obtain the packaging film with positioning holographic effect. In the application, the structure of the packaging film is designed, and the mold pressing and printing all-in-one machine is used, so that the packaging film with accurate positioning information is prepared, the positioning deviation of the graphic and holographic positioning mark is less than or equal to 0.20 mm, the preparation method is simplified, and the production efficiency is improved.

Description

A packaging film with positioning holographic effect, its preparation method and application Technical Field

[0001] This invention belongs to the field of holographic printing and packaging technology, specifically relating to a packaging film with positioning holographic effect, its preparation method, and its application. Background Technology

[0002] With societal development and changing consumer attitudes, consumers increasingly favor visually impactful product packaging. The combination of laser holographic anti-counterfeiting technology and traditional printing processes has resulted in new anti-counterfeiting packaging materials, which have been successfully applied in the packaging industry, such as cigarette packs, wine boxes, cosmetics, and toothpaste boxes. However, current laser holographic technology is primarily used in paper packaging, with its application in flexible plastic packaging being extremely rare.

[0003] CN102529475A discloses a method for preparing a laser holographic composite film. The method includes the following steps: printing an image layer on one side of a polyester film; then coating a UV varnish layer onto the printed image layer; transferring a holographic image layer onto the UV varnish layer; and finally vacuum-depositing aluminum onto the holographic image layer. The method for transferring the holographic image layer is as follows: coating a pre-made laser holographic BOPP film with UV varnish; pre-drying the polyester film and the laser holographic BOPP film, both coated with UV varnish; then laminating the two films; curing the UV varnish using an ultraviolet light device; and finally peeling off the cured film to obtain the holographic image layer transferred onto the UV varnish layer. This method is complex, and the laser holograms produced are all seamless plain surfaces, light pillars, and other full-page patterns, making it impossible to produce truly positioned holograms with personalized images such as cat's eyes or platinum reliefs. Furthermore, the large amount of UV varnish used in this method is prone to causing the migration of photoinitiators, making it unsuitable for mass production in food packaging.

[0004] CN205705618U discloses a plastic packaging material structure with positioning laser anti-counterfeiting. The structure involves printing graphic inks on a transparent plastic film, simultaneously printing UV coating, pressing it against a transparent biaxially oriented polypropylene laser transfer film, UV curing, and then separating the two layers, followed by vacuum aluminizing. While this method simplifies the process, it still relies heavily on UV materials. Furthermore, this process cannot achieve precise positioning of personalized graphics such as cat's eye patterns or platinum embossing.

[0005] Therefore, how to provide a packaging film that can accurately position personalized laser holographic images such as cat's eye and platinum embossing has become an urgent technical problem to be solved. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a packaging film with positioning holographic effects, its preparation method, and its applications. In this invention, by designing the structure of the packaging film and using a molding and printing integrated machine, a packaging film with precise positioning information is prepared, and the preparation method is simple.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a packaging film with a positioning holographic effect, the packaging film comprising a base film, a laser holographic layer, a graphic layer and a reflective layer stacked together.

[0009] In this invention, by stacking a laser holographic layer and a graphic layer on the base layer, the packaging film simultaneously achieves precise positioning and anti-counterfeiting effects.

[0010] In this invention, a molding and printing integrated machine is used to prepare a laser holographic layer and an image layer. The holographic micro-nano structure on the nickel plate is copied onto the laser holographic layer of the base film by heating and pressurizing. Then, image information is printed on the laser holographic information. The positions of the laser holographic layer and the image layer cannot be interchanged. If they are interchanged, it is impossible to use the molding and printing integrated machine to simultaneously prepare the laser holographic layer and the image layer, making the preparation method cumbersome. Secondly, due to the performance limitations of the printing ink used to prepare the image layer, it is impossible to perform a heating and molding process, and it is impossible to prepare the laser holographic layer by heating and pressurizing after preparing the image layer.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0012] As a preferred embodiment of the present invention, the base film is a transparent base film.

[0013] Preferably, the transparent base film includes any one of biaxially oriented polyester film, biaxially oriented polypropylene film, or polyethylene film, and more preferably biaxially oriented polyester film.

[0014] Preferably, the thickness of the base film is 10-100μm, for example, it can be 20μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm or 100μm, etc.

[0015] As a preferred embodiment of the present invention, the laser holographic layer is prepared by laser-molded information coating.

[0016] Preferably, the laser embossing coating is selected from composite laser embossing coatings or transfer laser embossing coatings.

[0017] Alternatively, the laser embossing coating is preferably an organic solvent-based laser embossing coating and / or a water-based laser embossing coating.

[0018] In this invention, the laser embossing information coating is preferably an organic solvent-based laser embossing information coating and / or a water-based laser embossing information coating. By using organic solvent-based laser embossing information coatings and / or water-based laser embossing information coatings to prepare the laser holographic layer, the problem of UV material photoinitiator migration is avoided.

[0019] It should be noted that there are no special restrictions on the selection of composite laser embossing coatings or transfer laser embossing coatings in this invention. Commonly used composite laser embossing coatings or transfer laser embossing coatings in the art are applicable. The composite laser embossing coatings include, but are not limited to, the coating with brand name DC-6060 from Danyang Runchi Coatings Co., Ltd.; the transfer laser embossing coatings include, but are not limited to, the coating with brand name DC-6020 from Danyang Runchi Coatings Co., Ltd.

[0020] Preferably, the thickness of the laser holographic layer is 0.5-8μm (e.g., it can be 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm or 8μm, etc.), and more preferably 1-4μm.

[0021] As a preferred embodiment of the present invention, the thickness of the graphic layer is 0.5-10μm, for example, it can be 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm, etc.

[0022] As a preferred embodiment of the present invention, the material of the reflective layer is selected from any one or a combination of at least two of aluminum, zinc sulfide, silicon dioxide or titanium dioxide, preferably aluminum.

[0023] Preferably, the thickness of the reflective layer is For example, it could be

[0024] or wait.

[0025] In a second aspect, the present invention provides a method for preparing a packaging film with a positioning holographic effect as described in the first aspect, the method comprising the following steps:

[0026] (1) Apply laser embossing information coating to one side of the base film. After drying, use an embossing and printing machine to emboss the laser hologram on the side of the laser hologram away from the base film. After embossing the laser hologram, print the graphic coating to form a laser hologram and graphic layer on one side of the base film.

[0027] (2) Prepare a reflective layer on the side of the graphic layer away from the base film to obtain the packaging film with positioning holographic effect.

[0028] In this invention, a packaging film with a positioning holographic effect is obtained by coating a transparent plastic base film with an embossing information coating and drying it, then simultaneously embossing a laser hologram and printing the corresponding color-coded images, followed by vacuum evaporation of a reflective layer. This invention solves the problem of positioning color-coded printing by completing the printing and embossing in one step, enabling precise positioning of personalized laser holographic images such as cat's eye patterns and platinum embossing.

[0029] As a preferred technical solution of the present invention, the laser holography includes any one or a combination of at least two of the following: cat-eye laser holography, relief laser holography, frosted laser holography, and brushed laser holography.

[0030] Preferably, the printing method includes gravure printing and / or flexographic printing, with gravure printing being more preferred.

[0031] As a preferred embodiment of the present invention, the molding and printing integrated machine includes a molding unit, a fixed-length stretching unit, and a printing unit.

[0032] The integrated molding and printing machine also includes an unwinding unit and a rewinding unit. The integrated molding and printing machine includes an unwinding unit, a molding unit, a fixed-length stretching unit, a printing unit, and a rewinding unit.

[0033] Preferably, the printing unit includes a positioning and overprinting system.

[0034] Preferably, the method for preparing the graphic layer using a molding and printing integrated machine in step (1) includes the following steps:

[0035] An integrated molding and printing machine is used to mold laser holography using its molding unit. Then, a fixed-length stretching unit is used to stretch the laser holography plate spacing to the circumference of the printing plate. Finally, the positioning and overprinting system in the printing unit is used to position and overprint the images and text, forming a laser holographic layer and an image layer on one side of the base film.

[0036] In this invention, the plate spacing of the laser hologram is stretched to the circumference of the printing plate using a fixed-length stretching unit, with the deviation controlled to be ≤±0.15mm, for example, it can be -0.15mm, -0.10mm, -0.05mm, 0mm, +0.05mm, +0.10mm or +0.15mm, etc.

[0037] In the figure, "+" indicates that the spacing between the stretched laser hologram and the printing plate is greater than the circumference of the printed plate, and "-" indicates that the spacing between the stretched laser hologram and the printing plate is less than the circumference of the printed plate, and the same applies below.

[0038] In this invention, after the positioning and color printing of the graphic text, the signal of the holographic positioning mark is identified by the tracking photoelectric eye, so that the printing accuracy deviation between the graphic text and the positioning hologram is ≤ ±0.20mm. For example, it can be -0.20mm, -0.15mm, -0.10mm, -0.05mm, 0mm, +0.05mm, +0.10mm, +0.15mm or +0.20mm, etc.

[0039] In this invention, the fixed-length stretching unit is a system that automatically adjusts the rotation speed of the servo traction roller in the fixed-length stretching unit by detecting the plate distance of the molded laser holographic film and comparing it with the circumference of the printing plate. This stretches the base film to a certain extent, adjusting the plate distance of the laser holographic film to be close to the circumference of the printing plate. This reduces the impact of plate distance changes caused by factors such as shrinkage due to film heating during molding and plate distance shrinkage after the tension is removed after molding the laser hologram under a certain stretching tension on the positioning and color matching printing.

[0040] As a preferred technical solution of the present invention, the method for preparing the reflective layer in step (2) includes vacuum evaporation.

[0041] Preferably, step (1) further includes a pretreatment step before coating the laser-molded information coating on one side of the base film.

[0042] Preferably, the pretreatment method includes corona treatment of the base film.

[0043] It should be noted that corona treatment can increase the surface tension of the base film. In this invention, laser-molded information coating is applied to the corona-treated side of the base film.

[0044] As a preferred embodiment of the present invention, the method for preparing the packaging film with positioning holographic effect specifically includes the following steps:

[0045] (1) Apply laser embossing information coating to one side of the base film, dry it, use an integrated embossing and printing machine, use its embossing unit to emboss laser holography, and then use a fixed length stretching unit to stretch the laser holography plate distance to the circumference of the printing plate, with the deviation controlled ≤ ±0.15mm. Then use the positioning and overprinting system in the printing unit to position and overprint the graphics and text. According to the tracking photoelectric eye to identify the positioning mark signal of the laser holography, the overprinting accuracy deviation between the graphics and the positioning holography is ≤ ±0.20mm, forming a laser holography layer and a graphics and text layer.

[0046] (2) A reflective layer is prepared by vacuum evaporation on the side of the graphic layer away from the base film to obtain the packaging film with positioning holographic effect.

[0047] Thirdly, the present invention provides an application of a packaging film with a positioning holographic effect as described in the first aspect, the packaging film being used to prepare packaging materials, labels, and daily chemical tubes.

[0048] Preferably, the packaging materials include food flexible packaging materials and tobacco and alcohol packaging materials.

[0049] Preferably, the label includes shrink label and daily chemical label.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] In this invention, by designing the structure of the packaging film and using an integrated molding and printing machine, a packaging film with precise positioning information is prepared. The positioning and overprinting deviation of the graphics and holographic positioning marks is ≤ ±0.20mm. At the same time, the preparation method is simplified and the production efficiency is improved. Attached Figure Description

[0052] Figure 1 is a schematic diagram of the structure of the packaging film with positioning holographic effect provided in Embodiment 1 of the present invention;

[0053] Figure 2 is a schematic diagram of the printing accuracy deviation between the image and the positioning hologram in the packaging film prepared after stretching the plate distance of the laser hologram to the circumference of the printing plate using a fixed-length stretching unit in step (2) of the packaging film preparation method provided in Embodiment 1 of the present invention.

[0054] Figure 3 is a schematic diagram of the discrepancy between the overprinting accuracy of the image and the positioning hologram in the packaging film prepared after step (2) of the packaging film preparation method provided in Comparative Example 1 of the present invention, without using the fixed-length stretching unit to stretch the plate distance of the laser hologram to the circumference of the printing plate.

[0055] Among them, 1-base film, 2-laser holographic layer, 3-image layer, 4-reflective layer. Detailed Implementation

[0056] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0057] The sources of some components in the following examples and comparative examples are as follows:

[0058] Composite PET polyester film: Changzhou Zhongheng high-brightness film, model HL;

[0059] Transfer-type PET polyester film: Changzhou Zhongheng transfer base film, model TP;

[0060] Composite laser embossing information coating: Danyang Runchi Coatings Co., Ltd., brand name DC-6060;

[0061] Transferable laser embossing information coating: Danyang Runchi Coatings Co., Ltd., brand name DC-6020;

[0062] Solvent-based ink: Zhejiang Xindongfang Chaolifu Gravure Ink, 3022-NTM-G.

[0063] Example 1

[0064] This embodiment provides a packaging film with a positioning holographic effect, the packaging film comprising a base film 1, a laser holographic layer 2, a graphic layer 3 and a reflective layer 4 stacked together;

[0065] The base film 1 is a composite PET polyester film with a thickness of 19 μm;

[0066] The laser holographic layer 2 is prepared by a composite laser-molded information coating and has a thickness of 4μm;

[0067] The graphic layer 3 is prepared from solvent-based ink and has a thickness of 0.5–2 μm;

[0068] The material of reflective layer 4 is aluminum, and its thickness is [missing information].

[0069] The preparation method for the above-mentioned packaging film is as follows:

[0070] (1) A laser embossing information coating is coated on one side of the corona-treated base film 1 and dried. The embossing printing machine is used to emboss the laser hologram using its embossing unit. Then, the laser hologram is stretched to the circumference of the printing plate using the fixed-length stretching unit. The deviation is controlled to be ≤ ±0.15mm. Then, the positioning and overprinting system in the printing unit is used to position and overprint the graphics. According to the tracking photoelectric eye, the positioning mark signal of the laser hologram is identified. The overprinting accuracy deviation between the graphics and the positioning hologram is ≤ ±0.20mm, forming the laser hologram layer 2 and the graphics layer 3.

[0071] (2) A reflective layer 4 is prepared by vacuum evaporation on the side of the graphic layer 3 away from the base film 1 to obtain the packaging film with positioning holographic effect.

[0072] Example 2

[0073] This embodiment provides a packaging film with a positioning holographic effect, the packaging film comprising a base film, a laser holographic layer, a graphic layer and a reflective layer stacked together;

[0074] The base film is a transfer-type PET polyester film with a thickness of 15 μm;

[0075] The laser holographic layer is prepared by a composite laser-molded information coating and has a thickness of 2μm;

[0076] The graphic layer 3 is prepared from solvent-based ink and has a thickness of 1–3 μm.

[0077] The material of reflective layer 4 is aluminum, and its thickness is [missing information].

[0078] The preparation method for the above-mentioned packaging film is as follows:

[0079] (1) Apply laser embossing information coating to either side of the base film, dry it, use an integrated embossing and printing machine, use its embossing unit to emboss laser holography, and then use a fixed length stretching unit to stretch the laser holography plate distance to the circumference of the printing plate, with the deviation controlled ≤ ±0.15mm. Then use the positioning and overprinting system in the printing unit to position and overprint the graphics and text. According to the tracking photoelectric eye to identify the positioning mark signal of the laser holography, the overprinting accuracy deviation between the graphics and text and the positioning holography is ≤ ±0.20mm, forming a laser holography layer and a graphics and text layer.

[0080] (2) A reflective layer is prepared by vacuum evaporation on the side of the graphic layer away from the base film to obtain the packaging film with positioning holographic effect.

[0081] Comparative Example 1

[0082] This comparative example provides a packaging film with a positioning holographic effect. The difference from Example 1 is that in step (2), the plate spacing of the laser holography is not stretched to the circumference of the printing plate using a fixed-length stretching unit. Other conditions are the same as in Example 1.

[0083] As shown in Figures 2 and 3, in this invention, the fixed-length stretching unit in the molding and printing integrated machine reduces the influence of plate distance changes on the positioning and color matching printing caused by factors such as the shrinkage of the film due to heat during molding and the plate distance shrinkage caused by the removal of tension after molding the laser hologram under a certain stretching tension, so that the printing accuracy deviation between the image and the positioning hologram is small.

[0084] Comparative Example 2

[0085] This comparative example provides a packaging film, which differs from Example 1 in that the packaging film includes a base film, a graphic layer, a laser holographic layer, and a reflective layer stacked together.

[0086] The preparation method of the above packaging film is as follows:

[0087] The image is printed on one side of the base film using a gravure printing machine, and then a laser holographic coating is applied to the side of the image. After drying, the holographic effect is positioned and molded using a holographic molding machine with positioning and color matching molding function. Finally, aluminum is vacuum-plated on the side of the laser holographic layer away from the base film.

[0088] The performance of the packaging films provided in the above embodiments and comparative examples was tested, and the specific test methods are as follows:

[0089] Place the packaging film in an environment with a temperature of 18-28℃ and a relative humidity of 50-70% for more than 8 hours, then lay it flat on a flat table and use a 20x magnifying glass with an accuracy of 0.01mm to measure the deviation between the printing registration line and the holographic registration line.

[0090] The performance test results are shown in Table 1 below:

[0091] Table 1

[0092] Positioning and overprinting deviation range: Example 1 -0.18 to +0.15; Example 2 -0.20 to +0.17; Comparative Example 1 -0.43 to +0.40; Comparative Example 2 -0.37 to +0.30. surface

[0093] In this invention, by designing the structure of the packaging film and using an integrated molding and printing machine, molding information coating is applied to a transparent plastic base film and dried. Then, while molding laser holography, the images and text are printed in line positioning and color matching. Finally, a reflective layer is vacuum-deposited, thereby obtaining a packaging film with positioning holographic effect. In this invention, printing and molding are completed in one step, solving the problem of positioning and color matching printing. It can achieve precise positioning of personalized laser holographic images and text such as cat's eye and platinum embossing. The positioning and matching deviation of the images and text and holographic positioning marks is ≤ ±0.20mm.

[0094] Compared to Example 1, if the fixed-length stretching unit is not used to stretch the laser hologram's plate distance to the circumference of the printing plate during the preparation of the packaging film (Comparative Example 1), the positioning deviation of the graphics and holographic positioning marks in the prepared packaging film is approximately ±0.50 mm. Therefore, it can be seen that in this invention, the fixed-length stretching unit reduces the impact of plate distance changes on positioning and color printing caused by factors such as film shrinkage due to heating during molding and plate distance shrinkage after the tension is removed following molding of the laser hologram under a certain tensile tension.

[0095] Compared with Example 1, if the graphic layer is bonded to the base film (Comparative Example 2), it is impossible to use a molding and printing all-in-one machine to simultaneously engrave the laser holographic layer and the graphic layer. In addition, the molding machine needs to have a positioning and color matching molding function, which makes the preparation method cumbersome and the production efficiency low.

[0096] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A method for preparing a packaging film with a positioning holographic effect, characterized in that, The preparation method of the packaging film includes the following steps: (1) applying laser molding information coating on one side of the base film, drying it, and then using a molding and printing machine to mold the laser hologram on the side of the laser hologram away from the base film, and then printing the graphic coating to form a laser hologram layer and a graphic layer on one side of the base film; (2) preparing a reflective layer on the side of the graphic layer away from the base film to obtain the packaging film with positioning holographic effect; the molding and printing machine includes a molding unit, a fixed-length stretching unit and a printing unit; the method of preparing the graphic layer using the molding and printing machine in step (1) includes the following steps: using the molding and printing machine, molding the laser hologram using its molding unit, then stretching the laser hologram plate distance to the circumference of the printing plate using the fixed-length stretching unit, and then using the positioning and overprinting system in the printing unit to position and overprint the graphic to form a laser hologram layer and a graphic layer on one side of the base film; the packaging film includes a base film, a laser hologram layer, a graphic layer and a reflective layer stacked together.

2. The method for preparing the packaging film according to claim 1, characterized in that, The base film is a transparent base film.

3. The method for preparing the packaging film according to claim 2, characterized in that, The transparent base film includes any one of biaxially oriented polyester film, biaxially oriented polypropylene film, or polyethylene film.

4. The method for preparing the packaging film according to claim 3, characterized in that, The transparent base film is a biaxially oriented polyester film.

5. The method for preparing the packaging film according to claim 1, characterized in that, The thickness of the base film is 10-100 μm.

6. The method for preparing the packaging film according to claim 1, characterized in that, The laser embossing coating is selected from composite laser embossing coatings or transfer laser embossing coatings.

7. The method for preparing the packaging film according to claim 1, characterized in that, The thickness of the laser holographic layer is 0.5-8 μm.

8. The method for preparing the packaging film according to claim 7, characterized in that, The thickness of the laser holographic layer is 1-4 μm.

9. The method for preparing the packaging film according to claim 1, characterized in that, The thickness of the graphic layer is 0.5-10 μm.

10. The method for preparing the packaging film according to claim 1, characterized in that, The material of the reflective layer is selected from any one or a combination of at least two of aluminum, zinc sulfide, silicon dioxide, or titanium dioxide.

11. The method for preparing the packaging film according to claim 10, characterized in that, The reflective layer is made of aluminum.

12. The method for preparing the packaging film according to claim 1, characterized in that, The thickness of the reflective layer is 250-600 Å.

13. The method for preparing the packaging film according to claim 1, characterized in that, The laser holography includes any one or a combination of at least two of the following: cat-eye laser holography, embossed laser holography, frosted laser holography, and brushed laser holography.

14. The method for preparing the packaging film according to claim 1, characterized in that, The printing methods include gravure printing and / or flexographic printing.

15. The method for preparing the packaging film according to claim 14, characterized in that, The printing method is gravure printing.

16. The method for preparing the packaging film according to claim 1, characterized in that, The printing unit includes a positioning and overprinting system.

17. The method for preparing the packaging film according to claim 1, characterized in that, The laser hologram's plate spacing is stretched to the circumference of the printing plate using a fixed-length stretching unit, with the deviation controlled to ≤±0.15 mm.

18. The method for preparing the packaging film according to claim 1, characterized in that, After the text and images are printed in color, the registration accuracy deviation between the text and images and the holographic positioning mark is ≤ ±0.20 mm based on the signal from the tracking photoelectric eye that identifies the holographic positioning mark.

19. The method for preparing the packaging film according to claim 1, characterized in that, The integrated molding and printing machine further includes an unwinding unit and a rewinding unit. The integrated molding and printing machine includes an unwinding unit, a molding unit, a fixed-length stretching unit, a printing unit, and a rewinding unit arranged in sequence.

20. The method for preparing the packaging film according to claim 1, characterized in that, The method for preparing the reflective layer in step (2) includes vacuum evaporation.

21. The method for preparing the packaging film according to claim 1, characterized in that, Step (1) includes a pretreatment step before applying the laser-molded information coating to one side of the base film.

22. The method for preparing the packaging film according to claim 21, characterized in that, The pretreatment method includes corona treatment of the base film.

Images