Includes 4 inkpads for use in layering stamps. CMYK stands for Cyan, Magenta, Yellow and Black. These are the 4 colours used to achieve all the colours that you see in colour photocopiers and printers. Use these 4 colours and layering stamps to create multi-coloured images. Better yet, use the Precision Press to make the stamping a breeze (sold separately). ,,With the Precision Press you can stamp anywhere, perfectly because it includes an 8" x 8" measurement grid for easy alignment and non-slip surface to keep projects in place. It's also brilliant for doing multiple stamping tasks, or for re-inking where necessary.