I have been making a lot of press-fit acrylic signs, but noticed one little problem… they warp after assembly. It’s not noticeable in some uses, in others it’s bad news.
I found that I could smash 'em flat with the heat press I use for making T-shirts, and it might work with a hand iron too.
- Find a flat, heat-proof surface
- Put your warped acrylic on the work surface
- Cover your arcylic with a heat-proof teflon sheet or similar (I bet a silicone baking mat would work)
- Warm your iron to ~180F
- Put the iron on top of the acrylic–weigh it down if you can. (Not sure how important the weight is, but my garment heat press delivers even pressure and it sure does the job.)
- Leave the heat on for about 15 minutes
- Turn the heat off but leave everything in place until it all cools off, about an hour
To truly anneal acrylic you need a longer period of both heating and cooling, but this quick method has made my signs nice and flat.