MONITORING THE FADING AND STAINING OF COLOR PHOTOGRAPHIC PRINTS
9 ADDITIONAL FADING MONITOR INFORMATION ON SPECIFIC COLOR PRINT MATERIALS
FADING MONITORS FOR instant materials, such as Polaroid 600, SX-70, Polacolor 2, Kodak Instant Color Film PR10, Kodamatic Instant Color Film, and Fuji Instant Color Film FI-10, should be prepared by optically printing the three density patches in the center of the prints. Since cutting or trimming such prints will alter their stability characteristics, the prints should remain intact for use as monitors. Kodak Ektaflex PCT instant darkroom color materials can be treated in the same manner as conventional color print materials, though great care should be taken in cutting Ektaflex patches to size. Both Kodak and Polaroid have been making changes in their instant color materials on a fairly frequent basis, and some of these changes alter stability characteristics. One should therefore ascertain that a monitor for an instant color print is made on the same material used for that print. The manufacturer can be consulted for advice on this point, but if there is any doubt, the print should be monitored directly and, if possible, in combination with the use of a print monitor. Polaroid 600, SX-70, Polacolor 2, and Polacolor ER prints in particular may have exceeded the suggested low-density stain formation limits (Table I) before they arrive in a museum collection. In such cases, the prints should be measured directly in low-density areas, and these readings should be compared with data obtained from identical materials shortly after they were processed (readings should generally be made about 24 hours after the processing of an instant print). As instant color prints usually have higher initial minimum density than other prints, low-density readings should be taken from areas of about 0.45 instead of 0.35 as suggested for other prints. The original Polaroid Polacolor film (now referred to as Polacolor 1) introduced in 1963 is no longer available, so prints made from this film must be monitored directly; these prints characteristically exhibit very good dark-storage stability and do not have the minimum-density stain problems associated with the later Polacolor 2 and Polacolor ER prints. Several other types of color prints, including Kodak Dye Transfer, Fuji Dyecolor, Cibachrome, Fresson Quadrichromie, and tricolor carbon/carbro appear to have very good dark-storage stability and freedom from stain formation; however, they are subject to light-fading. While these prints seem to have good room-temperature dark-storage properties, they should nevertheless be monitored for dark-storage changes that might eventually necessitate placing them in cold storage. Kodak Dye Transfer and pigment color prints are made with a variety of color layer sequences; if possible, the fading monitor should have the same layer sequence as that which was used to make the print being monitored. In the preparation of fading monitors for the chromogenic materials, such as Ektacolor RC papers, every effort must be made to follow the identical processing procedures (chemical process, the use or nonuse of Kodak Ektaprint Stabilizer-Process EP-3, wash time, wash water temperature, and pH) used to make the original print. The pH of the final wash water may have a significant effect on the dark-storage stability of the cyan dye and minimum-density stain formation in Kodak Ektacolor 78, 74 RC, and 37 RC papers. If the original processing conditions are unknown or uncertain, the original print should be monitored directly as well as by a separate fading monitor. Color transparencies, such as Lumiere Autochrome plates, can be monitored using the same general procedures outlined for direct monitoring of prints; however, a transmission densitometer will be required for taking density readings.
The author expresses appreciation to Carol Brower and Marcia Brubeck for their thoughtful assistance with the preparation of this article.