Burnishing:

Increase in gloss or sheen of paint film when subjected to rubbing, scrubbing or having an object brush up against it.

Possible causes:

• Use of matt paint in high traffic areas, where a higher sheen level would be desirable.
• Frequent washing and spot cleaning.
• Objects (furniture, for example) rubbing against the walls.
• Use of lower grades of paint with poor stain and scrub resistance (see Poor Stain Resistance and Poor Scrub Resistance)