Pantone is a propriety ink system that is the standard for colour matching and brand colours. Each ink is given a number and has a specific recipe so it can be mixed from standard ingredient inks. There are two main categories or colour books (named like that because the swatches are literally organized in books like paint chips), Coated and Uncoated. These are based on the paper that will be used, so colours for envelope printing should be picked from the Uncoated swatch book.

Pantone has a partnership with most common design software companies like Adobe so that the different colour books can be loaded from inside programs like Illustrator or InDesign and the desired colour chosen. This allows a designer to actually include the ink information in the file, making it very easy for the printer to know which ink to use.