# US 2013/0155421 A1 · Authentication of articles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155421 A1 - Document ID: US20130155421A1 - Status: Published application - Kind: A1 - Application number: 13/814,454 - Filed: 2011-09-09 - Published: 2013-06-20 - Earliest claimed: 2010-09-10 - Assignees: Innovia Films Limited - Inventors: Stephen Langstaff; Robert Stewart - Web page: https://patentgrep.com/patent/US20130155421A1 ## CPC - G01B 11/06: for measuring thickness {; e.g. of sheet material (thickness measurement by thermal means G01B21/085)} - G07D 7/12: Visible light, infrared or ultraviolet radiation - G07D 7/164: Thickness - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G07D: HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING ## Abstract The present invention provides a method of authenticating the provenance of an article marked with a transparent polymer film comprising measuring the thickness of the film or of a layer within in the film by white light interferometry and/or by birefringence. ## Claims ### Claim 1 A method of authenticating the provenance of an article marked with a transparent polymer film, comprising: measuring the thickness of the film or of a layer within in the film by white light interferometry and/or by birefringence. ### Claim 2 (depends on 1) The method of claim 1, comprising presenting the article marked with the polymer film to a detector such that light from the detector passes into the polymer film and is reflected back towards the detector from the surface of at least one layer within the film itself and/or from the surface of the article marked with the film. ### Claim 3 (depends on 2) The method of claim 2, wherein the surface of the article in a region marked by the film is opaque. ### Claim 4 (depends on 1) The method of claim 1, wherein the article is a moulded article. ### Claim 5 (depends on 4) The method of claim 4, wherein the article is marked with the film by means of labeling the article with the film. ### Claim 6 (depends on 5) The method of claim 5, wherein the labeling of the article with the film is effected by means of an in mould labeling process. ### Claim 7 (depends on 1) The method of claim 1, wherein no adhesive layer is present between the article and the film. ### Claim 8 (depends on 1) The method of claim 1, wherein the article is marked with the film by means of overwrapping the article with the film. ### Claim 9 (depends on 1) The method of claim 1, wherein the polymer film is affixed to the exterior of the article. ### Claim 10 (depends on 1) The method of claim 1, wherein the film is a multilayer film, and measurement is carried out on a core layer of the polymeric film. ### Claim 11 (depends on 10) The method of claim 10, wherein measurement is carried out on more than one layer within the film. ### Claim 12 (depends on 1) The method of claim 1, wherein the polymer film incorporates a clarifying agent. ### Claim 13 (depends on 1) The method of claim 1 according to any one of claims 1 to , wherein the article includes additional security features. ### Claim 14 (depends on 13) The method of claim 13, wherein the additional security features are included on or in the polymeric film. ### Claim 15 (depends on 13) The method of claim 13, wherein the additional security features are selected from one or more of holograms, taggants, “track and trace” codes or batch codes. ### Claim 16 (depends on 1) The method of claim 1, wherein the film is prepared by a bubble process. ### Claim 17 (depends on 1) The method of claim 1, wherein the film comprises a layer of biaxially oriented polypropylene (BOPP). ### Claim 18 (depends on 16) The method of claim 16, wherein the method differentiates between films made a bubble process and films made by a different process. ### Claim 19 (depends on 1) The method of claim 1, wherein the thickness of the film or a layer of the film is measured by birefringence and the film includes a light-reflective layer. ### Claim 20 (depends on 19) The method of claim 19, wherein the light-reflective layer is a metallised layer. ### Claim 21 A method of identifying an authentic article including a polymer film on the basis of the film meeting a specified pre-defined criterion of thickness and/or birefringence, comprising: measuring a thickness of the film or of a layer within in the film by white light interferometry and/or by birefringence. ### Claim 22 (depends on 1) The method of claim 1, wherein the article is a bottle or a lens, or a component part of a vehicular or electronic system. ### Claim 23 (depends on 1) The method of claim 1, wherein the article including a polymeric film which is to be authenticated is prepared by a process comprising the steps of: placing a polymeric film into a mould for injection moulding, thermoforming, or blow moulding; holding the label in position; injecting a melt into, or thermoforming or blowing a preform in said mould so as to bind with the label; and removing the article from the mould. ### Claim 24 A process for authenticating the provenance of an article,. comprising marking the article with a transparent polymer film and then measuring the thickness of the film or of a layer therein by means of white light interferometry or birefringence. ### Claim 25 (depends on 24) The process of claim 24, wherein the article is a moulded article labeled with the film by means of an in-mould labeling process, with no adhesive layer present between the article and the film.