I find that on my base metal, using Jax Black, if I leave the piece
in there too long (like, 2-3 minutes), the oxidation will always
flake off. It’s fine when left in for a shorter time.
The instructions say to stop the “oxidation” process by putting the
jewelry into water, but I find that it generally continues getting
darker, even after I put it in water (which is OK with me – I’m
trying for black). So I usually remove the jewelry from the Jax Black
when it’s dark brown, and then it gets more or less black while it’s
sitting in the water.