I’m slowly getting into texture painting in Blender, which is a ton of fun, but I’m standing in front of a problem:
I’m trying to paint my character’s skin and did so on a normal image texture fed into the BSDF. Now, I wanted to add freckles on a different layer so I won’t destroy the other texture. I generated a blank texture and combined it with the base skin texture with a MixRBG node – but it shows up as completely black on the character.
This isn’t just the case in Eeevee, which would be the usual suspect. A full render in Cycles also shows the texture as opaque and pitch black.
If you combine them on top of an opaque image/solid color then you can just layer them as in the example above. Base image > mix texture 1 > mix texture 2.
If you need their combined Alphas for something (transparency), you can mix Alpha channels separately from colors.
There’s also an interesting concept of texturing with “fill layers” (i’m no expert though, so recommend googling it).
Those made up of one solid color and a grayscale mask image. Mask goes into Fac and color into Color2. You can then adjust color whenever you wish.