Film Washi 120 Processing Leader

Overview

The Processing Leader is not a film: it is a blank, unsensitised plastic strip wound on a 120 spool, made by Film Washi for its own hand-coated paper films. The W-25 datasheet states the problem it solves — the emulsion sits on 28 g/m² Kozo washi rather than plastic, and "as they are very thin and flexible, paper based films cannot be loaded on modern processing reels". The maker's procedure is to tape the head of the film to the end of the leader with the leader underneath and the emulsion facing outwards, never taping onto the emulsion side; hold the two together and feed them into the reel's mouth with the emulsion now inwards and the leader outwards; load slowly and with extra care; then tape the far end of the film to the leader before closing the tank. The leader stiffens and guides the limp roll all the way in, and Film Washi describes it as a separating stripe — it stays between the coils so the paper cannot touch itself during development. Load in full darkness for the panchromatic Y-100; the orthochromatic W-25 may be loaded under a red safelight. The rest of Film Washi's published procedure for these films still applies: no acid stop bath (cold water instead), regular agitation and no stand development, fixing extended to 10–12 minutes because the back of the film rests against the leader, and at least 25 minutes of washing with a water change every 5 minutes. It is reusable — clean it, hang it to dry, then roll it back on its axis to protect it when not in use. For 120 W and Y only: Film Washi's polyester-base films load into a normal reel unaided, and the maker openly notes you can improvise the same thing from a blank strip of processed film, so what you are buying here is convenience and repeatability rather than necessity.