Blackening Titanium

Hi all,

I have a request from a customer for a Titanium ring that has to
have a blackened pattern. Colours I can do by means of anodizing but
black is not possible by that method.

Any ideas?
Shaun Pearton
@Shaun_Pearton

Heating to a red glow will make a dark grey oxide that is what I
think is being called black titanium.

Jim