I'm sure it's been covered but I couldn't find anything in the search.

I just aquired a bunch of birch bark that is still wet(green). It's still pliable.
What do I need to do to dry it for grip rings. I'm thinking of pressing it between two pieces of plywood with weight to get it flat and dry. what do others do? Also I've seen cutters made out of hole saws with the teeth ground off. Is this necessary or is leaving the teeth on OK? My bark thickness ranges from 1/8" to 1/4 "
Thanks.

Have never worked with green stuff so I can't help there but I use a regular hole saw with no problem. Some guys just cut it in squares

Mike (Southgate, MI)
If I don't want to, I don't have to and nobody can make me (except my wife) cuz I'm RETIRED!!

If you are using a hole saw you will have a 1/4 " hole in the center of each piece. I would put them all on a piece of all thread rod with a big flat washer and nut on each end , tighten them up until they are all flat and let them dry. Might take a couple of months unless you slowly bake the moisture out. You got to compress them while drying or they will just curl up. Then when you flatten them out, they split.
Birch bark is pretty smooth on the outside so you might not have to do any shaving off humps and knots. If they are not smooth on the outside, I would work on each piece before I compressed them,while they are still green. That's how I would do it . Someone else may have a different and better way of doing it . We have a bunch of bark enthusiasts on here.

Gary - I think you are on the right track. I would compress it between plywood, with weight on it. The slight to moderate curling is no problem, but you don't want heavy curling. It doesn't need to be 100% flat. I would make sure it can get air circulation so the bark all dries uniformly - oh, and it shouldn't take very long to dry at all - couple of weeks at most and it should be fine to work. The structure of bark is substantially different than the structure of heartwood or sapwood on a tree - drying characteristics should be much, much faster as it doesn't have the room to hold moisture like heartwood or sapwood.