I should metion that if you were to want to do a lot of switching sizes on film, a set of "rewinds" and a 35mm "split reel" would be useful. The split reel as the name implies comes apart with the two flanges attched to a center which will accept a 2 or 3 inch core. You can then wind the film off in the dark onto another roll using a set of rewinds. For my puroposes I generaly just use a spool on the other side, as it is hard to justify the cost of two split reels. I saved several 35mm spools from the Legacy Pro Bulk Film. (they spools are somecalled "daylight spools" or "Eyemo" spools if you are searching online to find them. You need rewinds that have a long enough spindle to accept 35mm rolls, some only are long enough for 16mm.