Heat patina copper before weaving it into chain maille.
Does the word annealing come to mind? Erm, not to mine, it didn't. Not before hitting it with the torch, anyway. Afterwards, oh yeah, that was all I could think of as I watched little rings pop off my bracelet when I tried to get it off my wrist after the clasp mushed up and refused to release!
Not to worry; I fixed it. I put the rings that had gone AWOL back, and hammered the clasp back into rigidness. I tumbled it, and for good measure, I hit it with my little plastic hammer to make sure it was good and hard.
It sure would have been easier had I made the decision to patina it before weaving it.