Quote:
Originally Posted by steven_e007  I got the impression from something that someone 'in the trade' said to me recently that maybe some of the European manufacturers are still using active gelatines in their traditional emulsion films and grade them carefully to get the required degree of sensitivity, rather than relying on adding compounds to de-activated gelatine.
Can anyone confirm this?
If it is true, then active gelatines should still be available at least in Europe.
Steve |
Steve;
Active gelatin is certainly available. It is merely unrefined bovine gelatin made from bones. The problem is the variability that is associated with each batch (high, medium or low ripenining for example) and who is going to test it for the individual.
The companies surely have tests from the 1900s that still work. If you can get them to sell it, fine. I find that there are enough variables to work with that I don't want to add this as well. I find it easier to adapt a formula rather than worry about getting old gelatin.
For that matter, unflavored Knox gelatin off the shelf is probably the 'old style', but IDK. The problem is that it has only about 50% gelatin, the rest being additives. So, you only get a percentage of the gelatin you want.
In my tests, the Knox supermarket gelatin gave very poor results for my emulsions.
PE