Ink

CMYK (Cyan, Magenta, Yellow and Black)
CMYK is a standard four color process used in commercial printing.

Pantone/PMS
Pantone is a standardized series of thousands of colors, each with specific color formulations and identification number. PMS colors are duplicated in swatch books and in computer-graphics programs to allow exact duplication of colors in printing and other marking processes. Types of pantones are Standard and Metallic Pantone

1 Colour Printing
Printing in either black, cyan, magenta, yellow or a pantone colour.

2 Colour Printing
Printing in any two colours (or a mix of any two colours) out of black, cyan, magenta, yellow or any 2 pantone colours.

3 Colour Printing
Usually printing in Cyan, Magenta and Yellow, or the same as for 2 colour printing except with one extra colour.

4 Colour Printing
Usually printing in Cyan, Magenta, Yellow and Black, or any mix of these colours or any 4 pantone colours.

4/4
Full-color process used on the front and back of printed materials.

4/1
Full-color front with a black back

4/0
Full-color front with a blank back

For example, a 4 page booklet printed 4/0 is really a 2 page booklet as only the outside pages will be printed the insides will be left blank.