In MyPaint, I've done it before, it's simple: paste the images in separate layers, then go to the top layer and start erasing at a low opacity. The bottom will be visible through the erased parts of the top.
Problem is, for some goddamn reason I can't get the two images to line up. Hell, I can't even get the second image to paste!
So I tried it in GIMP. Couldn't figure out anything past making the layers. Tried a tutorial. About a minute in, the guy says to change the brush size. Which would be useful if my copy of GIMP had the option to change the brush size, but it doesn't! Checked a dozen times to make sure I didn't miss a step somewhere, but nope: that option doesn't fucking exist. So that tutorial was utterly useless to me.
So I rage-quit a few minutes ago in frustration.
This was cross-posted from https://fayanora.dreamwidth.org/1443395.html
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