All coating consists of two primary ingredients— pigment and adhesive. The pigment provides the sheet with its brightness, ink holdout, smoothness, and gloss; however, pigment is a powder that must be bound to the sheet by an adhesive. (www.graphpros.com)

They tend to have good ink holdout and minimal dot gain, which can be especially important for recreating sharp, bright printed images, black and white halftones and four color process images. (disk.com)

Due to the non-absorbent substrate, ink holdout is maximized. This outstanding feature allows for many graphic effects to be achieved with combinations of opaque white for backing up images, leading to crisp contrasts which are ideal for 4 and 6 color work. (Vacumet Corp. )