re: metal ferruled brushes with platinum. It's a common question. For some reason, that dictum has gotten passed around in the platinum printing world since god was a kid. Like sightings of Elvis and JFK riding around together in a convertible in the Nevada desert, it sounds plausible, but doesn't prove to a problem in actual practice. I have been using the same Richeson brush for two years, and the only noticeable effect was that my prints got better. But the question always seems to come up. Anybody have an idea what book first mentioned that warning?