This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Washing Large Prints After Hypo. Have two trays 25x 30 inches, and four inches deep. Bore a row of half-inch holes around sides of tray one inch from top. This allows water to run off without carrying prints over the top. In washing use spray on each print, and change from tray to tray. Ten changes should remove the hypo.
Shaping Prints. For Aristo Platino or matte surface prints, run through a cold burnisher. If the mounts split, warm the burnisher just enough so you can hold your hand on the polishing roll. The warmth will prevent splitting. Use plain white cardboard between print and polishing roll.