Retouching Negatives for Printing
Portraits taken out of doors sometimes show unusually heavy shadows under the eyebrows and chin. The printing of these through the negatives may be altered by applying a little red or blue color on the glass side of the negative. Stippling the surface by contact with the texture of the skin also aids in removing the heaviness of such shadows.
Mat varnish, containing a small amount of iodine dissolved in it, and applied to the glass side of a negative, will cause much lighter prints than if the negative is permitted to remain with heavy shadows. The varnish will dry quickly, and it may then be scraped off carefully or removed with benzole from the parts of the negative which are not to be lightened. Care must be taken in scraping away the varnish in order to prevent scratches.