It looks like tumblr now automatically converts png files to jpg – if you have a fairly “clean”/simple digital art style that gets wrecked by jpg artifacts, you’ll want to put transparency somewhere in the image – tumblr will leave pngs with transparency alone (a single pixel border of transparency around the image works and is pretty non-intrusive).
Incidentally twitter has done this for a while, the same method of fixing it works there.
I’ve been doing this on twitter for months now; literally just adding a tiny border of transparent pixels is enough. .jpg does not support transparency, so adding it to the image forces Tumblr to maintain the .png file in order to maintain the transparency.
tumblr artist PSA?
