aaaaa i haven’t seen a post like this before so i figured i’d make my own? i hope a few people would find this useful cuz i don’t think everyone knows yet! anyway here we go:
Anything between 300-539 pixels width will be stretched to 540!
So 299 is the magic number to avoid tumblr blowing up your reaction images! What I also do is just set my canvas to 540 pixels and draw within that, if I think 299 pixels will be too small.
Of course, this only applies to the website and not the mobile app.
