Sometimes you will see us refer to numbers when describing your printing, for example: 4/0, 4/4, 4/1 or 5/4.
These numbers represent the numbers of colours on each side of your printing. Full colour printing is made from 4 inks: Cyan (C), Magenta (M), Yellow (Y), and Black (K) and is represented by 4. Black & White (or grayscale) is represented by 1 (although you can have many shades of gray). A blank side or no printing is represented by 0.
For example 4/0 would signify full colour printing on the front side with the backside being blank. 4/1 means full colour front and black & white on the back. 4/4 means full colour on both sides.
Sometimes you will see 5 used, this means that a 5th element, most often Metallix colours have been introduced to the printing process.