Methods of marking paper products and marked paper products are provided. Some methods include irradiating the paper product to alter the functionalization of the paper.

Methods of marking paper products and marked paper products are provided. Some methods include irradiating the paper product to alter the functionalization of the paper.

A visibly transparent, homogeneous UV-blocking cellulose nanocrystal/lignin nanocomposite film and a method of making the same. The film is made by dispersing cellulose nanocrystals and lignin in an aqueous, alkaline solution to yield a dispersion; casting the dispersion onto a substrate; and evaporating the aqueous, alkaline solution to yield a homogeneous, visibly transparent film that at least partially absorbs ultraviolet (UV) radiation.

A visibly transparent, homogeneous UV-blocking cellulose nanocrystal/lignin nanocomposite film and a method of making the same. The film is made by dispersing cellulose nanocrystals and lignin in an aqueous, alkaline solution to yield a dispersion; casting the dispersion onto a substrate; and evaporating the aqueous, alkaline solution to yield a homogeneous, visibly transparent film that at least partially absorbs ultraviolet (UV) radiation.

A method of forming a security document, comprises providing a thread comprising at least one region of heat-transformable material, this material having an optical effect which is transformable in response to applied heat. The thread is integrated with a document substrate material during a substrate forming process, so as to produce a security document substrate having at least one windowed region in which the thread is exposed at the substrate surface, and at least one bridge region in which the thread is not exposed. A patterned heat process is then applied, causing a structural modification in the heat-transformable layer of the thread so as to produce an observable optical effect representative of the heat pattern at one or more predetermined positions with respect to one or more of the said windowed region or bridge region. Security documents bearing threads with such optically transformable materials are also disclosed.

A method of forming a security document, comprises providing a thread comprising at least one region of heat-transformable material, this material having an optical effect which is transformable in response to applied heat. The thread is integrated with a document substrate material during a substrate forming process, so as to produce a security document substrate having at least one windowed region in which the thread is exposed at the substrate surface, and at least one bridge region in which the thread is not exposed. A patterned heat process is then applied, causing a structural modification in the heat-transformable layer of the thread so as to produce an observable optical effect representative of the heat pattern at one or more predetermined positions with respect to one or more of the said windowed region or bridge region. Security documents bearing threads with such optically transformable materials are also disclosed.

Disclosed herein are devices that change their appearance and/or physical properties when under an external influence, and methods for their production and use. Such devices may be used as features of any type of items, documents, billboards, posters, display devices, advertisements and other items etc. and may be adapted to include decipherable content. Such devices also afford new techniques for a user to check quickly and easily whether the item is a legitimate or a counterfeit copy, either by hand-manipulation of the device, or with the assistance of an additional screening tool.

Disclosed herein are devices that change their appearance and/or physical properties when under an external influence, and methods for their production and use. Such devices may be used as features of any type of items, documents, billboards, posters, display devices, advertisements and other items etc. and may be adapted to include decipherable content. Such devices also afford new techniques for a user to check quickly and easily whether the item is a legitimate or a counterfeit copy, either by hand-manipulation of the device, or with the assistance of an additional screening tool.

Methods of marking plastic-based products and marked plastic-based products are provided. Some methods include irradiating the product to alter the functionalization of the plastic. In general, the present disclosure features methods of marking substrates, e.g., substrates including plastics, such as plastic-based products, such as polymer banknotes. Such plastics can be rigid or flexible, e.g., elastomeric. Such plastics can be thermoplastic or thermosets. In some cases, the products are marked by irradiating plastic-based materials, e.g., sheet materials, under conditions that alter characteristics of the irradiated plastic.

Methods of marking plastic-based products and marked plastic-based products are provided. Some methods include irradiating the product to alter the functionalization of the plastic. In general, the present disclosure features methods of marking substrates, e.g., substrates including plastics, such as plastic-based products, such as polymer banknotes. Such plastics can be rigid or flexible, e.g., elastomeric. Such plastics can be thermoplastic or thermosets. In some cases, the products are marked by irradiating plastic-based materials, e.g., sheet materials, under conditions that alter characteristics of the irradiated plastic.