To clean most photographs without damaging them, apply a non-water based photographic emulsion cleaner such as PEC-12 with a soft cloth or cotton swab. Hire a professional photograph conservator to clean photographs from the 19th or early 20th century to prevent dissolving the emulsion.
Use an emulsion cleaner such as PEC-12 for color or black-and-white prints made on chemical-based paper. To apply, wipe the affected areas with a soft cloth or a cotton swab, moistened with one or two drops of PEC-12. Avoid using excessive amounts of PEC-12 to prevent leaving a white haze on the print.
Clean dye-sublimation prints with PEC-12 as well, but test on an unimportant area first to avoid potential damage. For recent negatives, apply PEC-12 with cotton balls or a cotton diaper. Do not use PEC-12 on acetate-based safety films manufactured prior to 1960.
To clean slides, use PEC-12 with a soft cotton cloth, but never spray the slide directly. Do not use PEC-12 on varnished slides. Clean moldy slides with PEC-12 or isopropyl alcohol.
Avoid using PEC-12 on chromogenic films, dye transfer matrix film, albumen, glass plate emulsion or Polachrome instant slide film.
For inkjet prints, avoid liquids and instead use dry cotton swabs, white cotton gloves or a microfiber cloth.