I've had some luck, depending on the size of the object to be removed, with a me dium to soft lead pencil. I learned this technique from a lady that was in a por trait studio with her husband. The pencil is a drafting pencil that you insert a large diameter piece of lead in. You then pull the lead out about an inch and a half. Using a very fine (1200 grit) sand paper, you twirl the lead between a fo lded over piece of sand paper, until you have a point about the size of a small needle. You can then retouch the negative, on the backing side, not the emulsion side. At least I have had the best luck on the back.

The nice thing about the lead, and working on the back of the negative, is the a bility to easily remove what you have done. Unlike spot tone or an ink, you can erase the lead and start over. This works especially well on spots, and with a l ittle practice, works on lint and hairs also.

She uses an Adams Retouching machine, basically a very small light box, in a big cabinet, that holds the negative, and that vibrates, to help blend the edges o f the spotting. I had a friend give me the same machine to get it out of his way , and it came with the leads and pencils, The name on the pencils and lead is, K oh-I-Noor. I have seen them in an Office Max, but I don't know if they were the same brand, but they definately were the same style of pencil.