Term used to describe the loss of sheen in a gloss finish.
Early loss of gloss may be caused by applying paint or varnish in unsuitable conditions, e.g. low temperature or high humidity, or to surfaces on which there is grease, oil, wax polish or other contaminant.

Failure to satisfy the porosity of the surface or the use of poor quality undercoats may result in sinkage of the finish and loss of gloss.

Over-thinning and the use of unsuitable thinners are other causes.  Some of the causes of loss of gloss may also cause slow drying.

If the coating dries satisfactorily and is otherwise not affected, application of a further coat will usually restore the gloss.