In the production of photographic prints, spotting is a type of retouching concerned with correcting minor flaws in the finished print with specially made paints and dyes. White spots on silver-gelatin prints are caused by dust adhering to the negative or paper during exposure. White spots can be carefully darkened using a fine paintbrush and a dye of the appropriate colour. A small amount of dye, which should be very weak, is needed. The spot will darken as dye accumulates in the gelatin layer. Black spots on silver-gelatin prints are caused by holes in the negative's emulsion. These can be removed by careful knifing of the gelatin layer. For spotting work, always use a magnifying glass and a good light source. [1]
