Law Enforcement soap, color additive help

[countymounty22]

I am planning on making a LEO soap for my brothers. It will be the thin blue line so the colors are black and blue. I have heard that prussia powder will not work. Does anybody have any tips on what kind of powder to use?

 

[lsg]

You can use ultramarine blue and activated charcoal powder for black.

 

[SoapySmurf]

I really like the blues i get using ultramarine blue. I don't recommend black oxide for the black, cause its always kinda grey anytime i use it. LSG is on the right track with the charcoal for the black.

 

[Pamela]

Ditto on the ultramarine blue and activated charcoal. I have added a little activated charcoal to my blue to make it a deeper blue rather than brighter blue.