| |
| |
 |
Some processed silver gelatin microfilms in storage for two to twenty years have developed small colored spots or blemishes. The fogged
leader at the outside of the roll is most frequently affected by the blemishes, which are generally red or yellow in color and are smaller in size than the image
characters (for example, a typewritten letter reduced 20X) on the microfilm. Other common areas for redox to start are fingerprints and areas where adhesive tape
is in contact with the film.
Once the deterioration of the microfilm occurs it cannot be reversed. The blemishes result in the permanent obliteration of the affected images. Silver film
duplication, molecular sieves, and Brown Toner can be used to stabilize the microfilm and prevent or slow degradation of as yet unaffected images.
Heritage Microfilm is the only commercial lab which Brown Tones all of its silver microfilm to prevent the onset of destructive redox.
|
| |
|
|