1) Marking 
• (p. pr. & vb. n.) of Mottle
Areas of color with no particular shape or pattern.
Snowflake type splotches and spots of white or sometimes differing color shades. Usually caused by high oil content.
Uneven impression, especially in flat areas - caused by too much pressure or unsuitable paper or ink. 
An area of skin comprised of macular lesions of varying shades or colours. ... Origin: E. Motley, variegated in colour ... (05 Mar 2000) ... 
(mot´ling) a condition of spotting with patches of color.
Type: Term Pronunciation: mot′ling Definitions: 1. An area of skin composed of macular lesions of varying shades or colors.
spots or blotches of different color or shades of color, as if stained
Mottling is the representation of the highlights and shades characteristic of natural wood, in its representation in graining.
[n] - the act of coloring with areas of different shades
A coating defect consisting of a non-uniform appearance of the cured coating in which the coating has a random, discontinuous poor flow or partial dewetted appearance.
noun the act of coloring with areas of different shades
A texturing seen in the smooth or monotone areas of an image that can be due to faulty processing and a number of improperly used digital processes, such as excessive unsharp masking.