A photoluminescent toner includes a photoluminescent toner particle that contains a binder resin, a release agent, and a photoluminescent pigment and has a release agent domain, and a silicone oil-treated silica particle that is externally added to the photoluminescent toner particle, in which in observation of a cross section of the photoluminescent toner particle, an average major axis length Dw of the release agent domain and an average major axis length Dp of the photoluminescent pigment satisfy Expression (1).

0.3≤Dw/Dp≤1.0  Expression (1):

A method of forming an image includes forming, on a recording medium (P), a special-light responsive image (201) that includes an image forming material including a special-light responsive image forming material that reacts to special light other than visible light and a special-light irresponsive image (202) that includes an image forming material including the special-light responsive image forming material. The special-light responsive image forming material of the special-light irresponsive image (202) is less than the special-light responsive image forming material of the special-light responsive image (201), and the special-light irresponsive image (202) is a prevention image that prevents visibility of the special-light responsive image (201). The forming includes forming an overlaid portion (203) in which at least a portion of one of the prevention image and the special-light responsive image (201) is overlaid on top of another one of the prevention image and the special-light responsive image (201).

A method of forming an image includes forming, on a recording medium (P), a special-light responsive image (201) that includes an image forming material including a special-light responsive image forming material that reacts to special light other than visible light and a special-light irresponsive image (202) that includes an image forming material including the special-light responsive image forming material. The special-light responsive image forming material of the special-light irresponsive image (202) is less than the special-light responsive image forming material of the special-light responsive image (201), and the special-light irresponsive image (202) is a prevention image that prevents visibility of the special-light responsive image (201). The forming includes forming an overlaid portion (203) in which at least a portion of one of the prevention image and the special-light responsive image (201) is overlaid on top of another one of the prevention image and the special-light responsive image (201).

A method of converting developer in a printer cartridge, comprising the steps: providing a developer unit of a printer cartridge; removing a first mixture of a developer and a first toner from the developer unit; sieving the first mixture of the developer and the first toner; removing the first toner from the first mixture of the developer and the first toner; mixing a second toner to the developer to create a second mixture of the developer and the second toner, wherein the second toner is a different toner than the first toner; and adding the second mixture of the developer and the second toner into the developer unit of the printer cartridge.

An image forming apparatus includes a first image forming part that forms a first image on a print medium using a photoluminescent developer containing a photoluminescent pigment; a second image forming part that forms a second image on the print medium using a coloring developer containing a coloring material; and a lamination part that laminates the first image and the second image on the print medium, wherein a viscoelastic phase angle (A) of the coloring developer and a viscoelastic phase angle (B) of the photoluminescent developer when measured at 125 [° C.] using a viscoelasticity measuring device satisfy follow:

21.1 [°]≤(A.Math.B)≤31.6 [°].

where A means a viscoelastic phase angle of the coloring developer, B means a viscoelastic phase angle of the photoluminescent developer.

An image forming apparatus includes a first image forming part that forms a first image on a print medium using a photoluminescent developer containing a photoluminescent pigment; a second image forming part that forms a second image on the print medium using a coloring developer containing a coloring material; and a lamination part that laminates the first image and the second image on the print medium, wherein a viscoelastic phase angle (A) of the coloring developer and a viscoelastic phase angle (B) of the photoluminescent developer when measured at 125[ C.] using a viscoelasticity measuring device satisfy follow:
21.1[](A.Math.B)31.6[]. where A means a viscoelastic phase angle of the coloring developer, B means a viscoelastic phase angle of the photoluminescent developer.

A color processing system includes one or plural processors configured to: acquire toner information indicating whether or not both a first condition, in which a special color toner to be added to a base color toner is a fluorescent toner, and a second condition, which is related to a printing order of the base color toner and the special color toner with respect to a recording medium on which an image is formed, are satisfied; and generate a color gamut, which is composed of the base color toner and the special color toner, by using a vertex of an outline of the color gamut corresponding to the toner information.

A photoluminescent toner includes a photoluminescent toner particle that contains a binder resin, a release agent, and a photoluminescent pigment and has a release agent domain, and a silicone oil-treated silica particle that is externally added to the photoluminescent toner particle, in which in observation of a cross section of the photoluminescent toner particle, an average major axis length Dw of the release agent domain and an average major axis length Dp of the photoluminescent pigment satisfy Expression (1).
0.3Dw/Dp1.0Expression (1):

In a general aspect, identity markers containing identity-forming particles are created by electrostatic printing processes. In some aspects, a toner mixture is received on an electrostatically charged surface of an image transfer drum in an electrostatic printer system. The toner mixture includes fusible particles and diamond particles. The toner mixture is held to the electrostatically charged surface by an electrostatic force. The toner mixture is transferred onto a substrate from the electrostatically charged surface of the image transfer drum. The toner mixture is bonded to the substrate by operation of a fuser assembly of the electrostatic printer system. When the toner mixture is bonded onto the substrate, the fusible particles fuse to each other, thereby forming a host matrix that secures the diamond particles at fixed locations in the host matrix.