The Pantone Colour Matching System is largely a standardized colour reproduction system. By standardizing the colours, different manufacturers in different locations can all refer to the Pantone system to make sure colours match without direct contact with one another. The Pantone Matching System (PMS) is a proprietary colour space used in a variety of industries, primarily printing, though sometimes in the manufacture of coloured paint, fabric and plastics. The Pantone colour guides have been widely adopted and are used by artists, designers, printers, manufacturers, marketers and clients in all industries worldwide for accurate colour identification, design specification, quality control and communication. Pantone recommends that PMS Colour Guides be purchased annually, as their inks become yellowish over time. Colour variance also occurs within editions based on the paper stock used (coated, matte or uncoated).