You can retouch prints or negatives. However, you will save time by retouching a negative if you plan to make many prints from it. The techniques described in this pamphlet apply to color negatives made on Kodak films. The tools you need are also similar, except that you won't use an etching knife. You build up the density of color negatives by applying dyes or black lead, and you change the color by using colored dyes or colored pencils or a combination of dyes and pencils.
Improper film drying can adversely affect the retouching characteristics of negatives.
Avoid over- or underdrying the film, drying it too quickly or too slowly, or winding the film with excessive tension if it is hot. A proof print will help you determine the amount of retouching a negative requires. As you gain experience, you will find it easier to predict the effects of retouching. The colors in the negatives are approximately complementary to the colors in the original scene. Contact the manufacturer of your retouching machine for information about lamp modification.