There are a couple of things that cause yellowing and fading.
First, some papers are made of cellulose from trees. This type of paper can yellow over time when it comes in contact with acids in the air. One of the best ways to stop this, is to store the prints in archival storage products. If you mount the prints, use a buffered matte. A buffered matte has a chemical that actually neutralizes acids.
The best bet is to use an archival paper. These papers are typically made from cotton instead of tree fibers. If it is black and white, you can wash the print in pH neutral water for several hours, and follow with toning the print with a selenium toner to remove the slightly acidic sliver halides. A selenium toned print on cotton rag should last for hundreds of years.
Color prints can yellow for a number of reasons. A traditional C-type print uses dye-coupled silver halides. When you process the prints, the silvers are rinses away leaving the dyes on the paper. All dyes degrade over time, and since yellow dyes last the longest, the print will appear to turn yellow.
This can be prevented by using a pigment inks instead of dyes to create color prints. Inkjet printers work best for this, but you should still print on archival cotton rag paper. Nothing can be done to prevent dye prints from color shifting with time, but you can slow the process by using a UV glass when framing the prints.
· 8 years ago