Opacity
How well a paint or ink hides what is underneath it.
Also: hiding power, transparency, covering power
An opaque paint covers the surface below in one coat. A transparent one lets it show through, like coloured glass. Opacity depends on the pigment and on how much is used. Titanium white is very opaque; many deep reds and blues are transparent. Neither is better. House painters want hiding power. Artists use transparent colours for glazing and opaque ones for solid passages. In digital design, opacity is a setting from 0 to 100 per cent that controls how much of the layer below shows through.