Quote Originally Posted by jvuokko View Post
I checked some of those film backs with dark slide pulled out but still attached to the back (like some LF photographers does). It was a surprise to see that hanging dark slide let more light come out from the film back's slot than completely removed dark slide.
There is a light trap consisting of a spring and some velvet-like material that allows the darkslide to pass but closes behind it when the darkslide is pulled. The spring generally won't wear out but the black material will. I'm not certain of the best replacement but it can be disassembled and the light trap material replaced.