Yeah, it was created as entirely transparent. I created 5 in total, painting each one then creating a new one. This was the second one. I left blender minimized for a while, ~6 hours, and when I returned to blender this one had reverted to entirely transparent. I’ve checked all the other images in the blend and they are as expected.
It would seem I am not alone:
Two people make similar claims:
Looks like you didn’t save your texture regularly while painting, so all your strokes were on ram, which was needed when you started doing something else.
Yeah, Blender doesn’t really save texture changes until you tell it to-- it keeps it in volatile memory, and eventually, it decides it doesn’t need that memory anymore. It’s dumb, it’s annoying, it probably qualifies as a bug but I’ve never reported it.
Obviously can’t confirm that’s what is actually happening but it fits. I wouldn’t expect an image to be wiped even if it was unsaved, provided the program remained open the entire time.