In the production of photographic prints, spotting is a type of retouching flaws in the finished print with specially made paints, dyes, pencils and pens.
Prints from positive transparencies exhibit black marks.
White spots can be carefully darkened using a fine paintbrush and a dye of the appropriate colour.
Black spots on gelatin-silver prints are caused by holes in the negative's emulsion.
For spotting work, always use a magnifying glass and a good light source.