It usually curves if you over melt it. Trust me, I have the same problem because I like my projects flat. There really isn’t an easy way to fix it other than try to push it down with whatever hand you aren’t using to iron it. (and also use oven mitt so you don’t burn your hand). I know its hard but it’s one of those things that can’t be avoided unless you don’t iron it quite so much.
I hope this helped somehow. (:
Just in case there’s anyone else wondering this, the easiest way I know is to use the tape method (video tutorial here). Your bigger sprites sometimes still curl up but you just put something heavy on it and come back to it later - it stays intact because it’s attached to the tape.
Awesome things about the tape method:
If videos aren’t your thing, here is a blog post with bullet points & pictures instead.
Note: I’ve seen people post pictures with uneven melting and say it has something to do with the masking tape trapping air. I don’t iron very heavily and I rarely iron the front of the project at all, so I haven’t had a problem with this but if you prefer to seriously melt your sprites or you care about how your B-side looks or you can see the uneven melting from the display side of the sprite, I’ve seen it suggested that you poke holes in the masking tape - more on that here.#perler #hama #nabbi #pixel #tutorial #masking tape #tape method