[LargeFormat] Film Holder Testing

[Ole Tjugen]

If you use ordinary enlarger paper to test film holders with, you can simply write a number on the sheets before loading - in darkroom 
safelight.

My holders are numbered sequentially, the first holder holds films A1 and A2, the second one B1 and B2 and so on. If I were to test my 
holders now, I would use 4x6 single-weight paper, cut off an inch from the end, write A1, A2, B1,B2,C1,C2 and so on with BIG letters in 
waterproof ink on the back side of each sheet. I would then load them in the corresponding holders and wait for a sunny day. Unfortunately 
I didn't do this, but instead believed that new holders must be good. They weren't. But since my holders are numbered, I was able to find 
the faulty one anyway: By always starting with A1 it was easy to find out that holder A was indeed leaking light - on both sides. 

Ole Tjugen