In the film envelope, there was a ‘sac’ of developer gel. When you processed the film by pulling it out of the holder, the two stainless steel rollers crushed the pod and spread the gel over the image surface. That’s why it was critical to pull steadily and carefully.

https://www.photo.net/discuss/threads/rb67-w-polaroid-back-first-tests-and-failures.5509574/

բնօրինակ սփիւռքում(եւ մեկնաբանութիւննե՞ր)