Looking for help with cold casting details on mold

I have a Black panther mold I have made and I want to cold cast with metal details the silver detailing on the mask with aluminum powder. I cant seem to get the powder to stay in the spots I want, Is there any tip to this or do I have to do the entire helmet and just polish the parts I want?

For maximal results, cold casting will need powder in the mold and powder in the resin.

Doing parts / lines in your helmets seems very tedious! I would go with all the helmets and paint the black over or no cold cast at all and then paint your parts silvers like most do. There’s tons of examples of this technique with the kylo ren helmet which is similar in result.