Thanks for the reply. I've also heard from Zac at NV woodwerks he suggested to let the resin heat to between 95 and 125 before pouring.Are you asking about dye powder (soluble) or mica powder (non-soluble)?
You can freely mix liquid dye and mica powders to give a colored iridescent blank.
If you want to mix a powdered dye and a liquid dye, don't really know as I've not tried it, but I don't see why not.
If you want a swirled blank with several colors that are not mixed, then prepare your resin and mix it well, then add your dye just before pouring; or you can pour into your mold, add dye, and use a little stick or toothpick to partially mix. You can also prepare separate cups of resin, each with a different color, and then mix them while pouring, or pour one cup into the mold and then add the next colored cup of resin (pouring slowly to minimize mixing. You can pretty much do whatever you want in this regard, there aren't too many rules, your imagination is the limit as long as your follow directions for the resin.
There are lots of youtube videos showing how to do this in different ways.
nice.Tim, I just cast two 1.75x1.75x6 blocks yesterday using Zacs temp method. Worked fairly well but I'm still learning. I had really good separation but I may have over mixed it a bit.
This is Alumalite Clear with mica powders. I have mixed alcohol inks into resin with the micas with success.