A printer who provides offset printing services will use offset presses and a specific process to create finished printed materials. The process works on the basic principle that ink and water do not mix, so that the ink only adheres to the area to be printed. Water is used on all areas that will be left blank and will not be printed on.
The offset process does not use the traditional method of printing where the ink is placed on a plate and then applied directly to the paper. Instead, a rubber blanket or mat is used, and the ink is offset onto the blanket and then applied to the paper from the blanket instead of directly from the printing plates. Printing companies often offer these services to clients because of the many advantages.
The printing process that uses a blanket to receive the ink from the plate and then impresses it onto a sheet of paper as the paper passes between the blanket and a hard steel cylinder called an Impression Cylinder.