I came to 4x5 through the 6x6. That's why I crop my latest works. I've tried 4x5 frames but couldnt get with it, so I made mask on my rear standard, and my F2 now shoots 4"x4" squares ;]
Very short (really short=>20secs) rinse after fixing and bleaching during sepia toning caused funny streaks which made those shots look like they were really old.
and here is 4x5 frame that I shot earlier, with no experiments
all pics were taken with symmar s 300/5,6 and all of them were contact printed on expired in 1985 ORWO BN1 paper, and then toned with sepia and selenium toners.