Electronic ink paper includes: an image display area comprising a support layer, a conductive layer on the support layer, an ink layer on the conductive layer and to display an image by electrophoresis of pigment particles dispersed in an electrophoretic liquid, and a transparent surface layer to cover the ink layer; and a border to surround the image display area and including at least one edge having a tapered shape that decreases in thickness toward the outside of the border.

Described herein is a process for heat transfer printing, the process comprising: electrostatically printing a transparent release composition onto a transfer material to form a release layer disposed on the transfer material; electrostatically printing an electrostatic ink composition on the release layer to form an image layer disposed on the release layer; contacting a thermoplastic film with the image layer; contacting the thermoplastic film with a target substrate under conditions such that the thermoplastic film adheres to the target substrate and the release layer is softened; and separating the target substrate and the transfer material such that the thermoplastic film, image layer and release layer are transferred to the target substrate. A heat transferrable printed image is also described herein.

Described herein is a process for heat transfer printing, the process comprising: electrostatically printing a transparent release composition onto a transfer material to form a release layer disposed on the transfer material; electrostatically printing an electrostatic ink composition on the release layer to form an image layer disposed on the release layer; contacting a thermoplastic film with the image layer; contacting the thermoplastic film with a target substrate under conditions such that the thermoplastic film adheres to the target substrate and the release layer is softened; and separating the target substrate and the transfer material such that the thermoplastic film, image layer and release layer are transferred to the target substrate. A heat transferrable printed image is also described herein.

A method of producing a material with a perovskite structure on a substrate by liquid electrophotographic printing comprises: either liquid electrophotographically printing onto the substrate a composition comprising a dispersion of a salt AX and a thermoplastic resin in a carrier liquid; liquid electrophotographically printing onto the substrate a composition comprising a dispersion of a salt selected from BX2 and BX4 and a thermoplastic resin in a carrier liquid; and heat treating the printed compositions to form the material with a perovskite structure; or liquid electrophotographically printing onto the substrate a composition comprising a dispersion of a material with a perovskite structure and a thermoplastic resin in a carrier liquid to form the material with a perovskite structure; wherein A is a cation, B is a cation and X is an anion; wherein the thermoplastic resin comprises a copolymer of an alkylene monomer and a monomer having acidic side groups.

Described herein is process for heat transfer printing, the process comprising: liquid electrostatically printing a liquid electrostatic ink composition on a polyether-based thermoplastic polyurethane film to form a printed film; and contacting the printed film with a target substrate under conditions such that the printed film adheres to the target substrate. Also described herein is a process for printing a heat transferable printed image and a heat transferable printed image.

Described herein is process for heat transfer printing, the process comprising: liquid electrostatically printing a liquid electrostatic ink composition on a polyether-based thermoplastic polyurethane film to form a printed film; and contacting the printed film with a target substrate under conditions such that the printed film adheres to the target substrate. Also described herein is a process for printing a heat transferable printed image and a heat transferable printed image.

Described herein is a process for heat transfer printing, the process comprising: electrostatically printing a transparent release composition onto a transfer material to form a release layer disposed on the transfer material; electrostatically printing an electrostatic ink composition on the release layer to form an image layer disposed on the release layer; contacting a thermoplastic film with the image layer; contacting the thermoplastic film with a target substrate under conditions such that the thermoplastic film adheres to the target substrate and the release layer is softened; and separating the target substrate and the transfer material such that the thermoplastic film, image layer and release layer are transferred to the target substrate. A heat transferrable printed image is also

Described herein is a method of producing a perovskite material on a substrate by LEP printing comprising: printing a composition comprising a salt AX and a resin in a carrier liquid; printing a composition comprising a salt selected from BX.sub.2 and in BX.sub.4 and a resin in a carrier liquid; and heat treating the printed compositions; or printing a composition comprising a material with a perovskite structure and a resin in a carrier liquid; wherein the resin comprises a copolymer of an alkylene monomer and a monomer having acidic side groups; and/or a copolymer of an alkylene monomer and an ethylenically unsaturated monomer comprising an epoxide; and/or a copolymer of an alkylene monomer, an ethylenically unsaturated monomer comprising an epoxide, and a monomer selected from a monomer having acidic side groups, a monomer having ester side groups and a mixture thereof. Also described is an ink set and a printed substrate.

An electrostatic screen printer includes: an electrically conductive screen arranged in non-contact with a printing medium; sponges for rubbing a powder into the screen; and a direct current power source for applying a voltage to the printing medium and the powder, wherein the powder rubbed into the screen is adhered to the printing medium by electrostatic induction. The electrostatic screen printer includes a rotation mechanism for rotating the sponges, a parent revolution mechanism for parent revolution of the sponges, and a child revolution mechanism for child revolution of the sponges. The revolution speed ratio of the child revolution to the parent revolution may preferably be 4.0 or greater, a scraper is provided on the parent revolution mechanism so as to be interlocked with the revolution of the sponges, and the scraper is arranged so as to scrape the powder on the screen toward an axis of the parent revolution because of the interlocking.

An electrostatic screen printer includes: an electrically conductive screen arranged in non-contact with a printing medium; sponges for rubbing a powder into the screen; and a direct current power source for applying a voltage to the printing medium and the powder, wherein the powder rubbed into the screen is adhered to the printing medium by electrostatic induction. The electrostatic screen printer includes a rotation mechanism for rotating the sponges, a parent revolution mechanism for parent revolution of the sponges, and a child revolution mechanism for child revolution of the sponges. The revolution speed ratio of the child revolution to the parent revolution may preferably be 4.0 or greater, a scraper is provided on the parent revolution mechanism so as to be interlocked with the revolution of the sponges, and the scraper is arranged so as to scrape the powder on the screen toward an axis of the parent revolution