<#tagging> with an uneven, rough, or dappled appearance when viewed under ultraviolet light, as opposed to <#even> or <#grainy=grainy tagging>. Some causes of mottled tagging are uncoated paper, worn tagging rollers, and offsetting of wet <#taggant> ink when sheets are stacked. Example: 1991 Dennis Chavez stamp, <#scott=Scott> 2186.