What information is available on your gelatin recording medium and is it stable over time?

Our gelatin recording medium is very similar to the gelatin that has been used in the photography industry for more than 100 years. As you may know, properly processed photographs are very stable and will retain their properties for decades. One of the major reasons for this excellent stability of photographs is the stability of the gelatin base. The discoloration of very old black and white photographs is a result of insufficient removal of fixer from the paper base, which results in a yellowing of the paper. It has nothing to do with the gelatin.

Wasatch Photonics uses a dichromated gelatin (DCG) mixture as its recording medium of choice. Once this mixture is processed and the chromium removed, it is essentially pure gelatin and is very stable. During the past thirty years, there has been no measurable degradation in gelatin gratings that are properly sealed. The DCG holographic scanning disks used in some of the early optical bar code scanners still function exactly as they did over 20 years ago.