Step five of my mask-creating. This is the mask with an undercoat, ready for painting. I had to go shopping for paints, and I was looking at the range of acrylic paints, and one of the ranges offered three different types of black. I consider "blue-black" to be the "truest" looking black, but I wanted the mask to have a red-slant (to the point that I was intending to use very, very, very, very dark red on the mask, and only use actually black for the undercoat). So, I bought a tube of "red-black" to use as the undercoat. When painting with the red-black, it looked very brown, but it was noticeably darker when dry.
The details are kinda hard to make out, cause it's all black, but hopefully it will all be clear in the final pictures! This was UNDENIABLY the easiest part of the entire process. Paint brush, tube of paint, palette, go.