Laser printing The laser printing process is very similar to the xerographic photocopying process. The major difference is that the exposure step for laser printers employs a laser beam to draw the image onto the sensitised surface to form the latent electrostatic image. That is, each colour is separately laid onto the paper. A typical dry toner is predominantly composed of a heat-sensitive polymer, acrylic or styrene, or both. The next major ingredient is a pigment such as carbon black.
Carriers are an active ingredient in a toner.
They are used to generate a charge on the toner particles. The carrier is typically an iron or steel powder, which may be coated with resin. The presence of carriers in the image formed on paper may adversely affect the stability and longevity of documents, particularly those created by the liquid process. Dry toners mostly remain on the surface with little penetration of the paper fibres, therefore the effect of carriers is lessened. Some toners do not contain carriers.