Abstract: In an example, a method includes identifying a contact area of a substrate within which an apparatus will make contact with the substrate and defining a boundary area of the substrate between the contact area and a remaining area of the substrate. Print agent may be printed on the substrate, wherein the print agent is printed at a first coverage in the remaining area, a second coverage less than the first coverage in the contact area; and a gradually reducing coverage across the boundary area from the first to the second coverage.

Abstract: Method and devices for calibrating optical density reflective color fluids to be deposited on substrate are disclosed. Some methods comprise depositing a quantity of a keying color fluid on a first region of the substrate; applying a voltage level to a reflective color fluid application device; depositing, in response to the voltage level applied, a quantity of reflective color fluid on the first region of the substrate and on a second region of the substrate; performing reflectance measurements of the first region and of the second region; performing optical density calculations as a function of the reflectance measurements; varying the voltage level applied to the reflective color fluid application device in response to said optical density calculation until the optical density calculation is within a calibrated range of optical densities.

Abstract: Example aspects described herein relate to an apparatus for adjusting control parameters of a printing substance for a printing system. Such adjustments may occur in conjunction with a color calibration process of the printing system.

Abstract: Method and devices for calibrating optical density reflective color fluids to be deposited on substrate are disclosed. Some methods comprise depositing a quantity of a keying color fluid on a first region of the substrate; applying a voltage level to a reflective color fluid application device; depositing, in response to the voltage level applied, a quantity of reflective color fluid on the first region of the substrate and on a second region of the substrate; performing reflectance measurements of the first region and of the second region; performing optical density calculations as a function of the reflectance measurements; varying the voltage level applied to the reflective color fluid application device in response to said optical density calculation until the optical density calculation is within a calibrated range of optical densities.

Abstract: Example aspects described herein relate to an apparatus for adjusting control parameters of a printing substance for a printing system. Such adjustments may occur in conjunction with a color calibration process of the printing system.

Abstract: The present disclosure relates to an electrophotographic composition that comprises a polymer resin mixture and a liquid carrier. The polymer resin mixture comprises (i) an olefin polymer A having acid and/or ester side groups and a melt index of 22 to 100 g/10 min; and (ii) an olefin polymer B having a melt index of 1 to 20 g/10 min. The olefin polymer B forms 1 to 50 weight % of the polymer resin mixture.

Abstract: In an example, a method includes identifying a contact area of a substrate within which an apparatus will make contact with the substrate and defining a boundary area of the substrate between the contact area and a remaining area of the substrate. Print agent may be printed on the substrate, wherein the print agent is printed at a first coverage in the remaining area, a second coverage less than the first coverage in the contact area; and a gradually reducing coverage across the boundary area from the first to the second coverage.

Abstract: Herein is disclosed an electrostatic ink composition. In some examples, the electrostatic ink compositions comprise: a carrier liquid; a first resin; and a fluorescent pigment. The fluorescent pigment comprising a fluorescent dye and a second resin matrix, wherein the second resin is selected from the group comprising polyamide resins, polyvinylchlorides, polyolefin resins, polystyrenes, acrylonitrile-butadiene-styrene resins, polycarbonates, poly acrylic and methacrylic acid resins, polyethylene terephthalates, polyamide resins, polyurethanes, epoxy resins, silicone resins, polyester resins, alkyd resins, acrylonitrile polymers, polyesteramides or combinations thereof.

Abstract: The present disclosure relates to an electrophotographic composition that comprises a polymer resin mixture and a liquid carrier. The polymer resin mixture comprises (i) an olefin polymer A having acid and/or ester side groups and a melt index of 22 to 100 g/10 min; and (ii) an olefin polymer B having a melt index of 1 to 20 g/10 min. The olefin polymer B forms 1 to 50 weight % of the polymer resin mixture.

Abstract: Herein is disclosed an electrostatic ink composition. In some examples, the electrostatic ink compositions comprise: a carrier liquid; a first resin; and a fluorescent pigment.

Abstract: An example method of controlling a printing process in accordance with aspects of the present disclosure includes controlling an optical density of a printed image such that the optical density is increased for a predetermined portion of a leading edge of a page.

Abstract: An example method of controlling a printing process in accordance with aspects of the present disclosure includes controlling an optical density of a printed image such that the optical density is increased for a predetermined portion of a leading edge of a page.