Litho printing is an ideal method of print for images with gradients of colour. The image must be supplied as 'pixel' artwork made from CMYK separations.
Litho printing uses a technique where the inked image is placed on a printing plate (usually zinc/aluminium) in a series of dots, made from Cyan, Magenta, Yellow, Black (CMYK). this is then imprinted on a rubber cylinder and then transferred (offset) to the disc.
See example to the right.