How to safely remove an unknown type of glue from acrylic lamp shade.

Possibly an acetone-type nail polish remover will work. You can also buy acetone by itself. It should work. Maybe let it soak by applying with a cotton ball or soft scrap of fabric.

here is some info for you to try

https://www.hunker.com/13419628/how-to-remove-adhesive-from-acrylic

https://www.ontimesupplies.com/solutions/remove-adhesive-residue-from-anything-with-these-diy-solutions

First try a small spot with the nail polish remover and see if it affects the acrylic. It can melt the plastic or even give it a rougher surface. I actually would use fine grit sandpaper and sand the glue off to be safe

Besides trying acetone I would also consider trying mineral spirits. Of course make sure and test it first so it doesn't do damage.

Are you able to lift the edge so you can peel it off? Sometimes a hot cloth with help lift it. Good luck!

Try heating with a blow dryer enough to lift the edge. Then you could peel it.

I would try a paper towel moistened with water soak —then try an old gift card or credit card as a scraping tool that would not damaged the acrylic. Using a razor scraping tool might be very carefully attempted with extreme attention and an angular approach.

Try to scrape with a razor

That is a tough one. If the glue is hard then it possibly could be removed with a Dremel tool. Be very careful

I would try to use a razor blade to get under edge of glue.

I like the idea of razor blade. Or maybe try sanding and then giving it a fresh coat of paint?

I always use peanut butter to remove sticky stuff. I think it's the oil and the bit of grit, but it always works. Good luck!

If all else fails, try to locate an acrylic manufacturer and ask them what might work best given the material. Be very very careful with things like acetone or paint thinners, that could ruin the acrylic.

Hello, hope this helps you out,

https://www.loctiteproducts.com/en/know-how/fix-stuff/how-to-get-sticky-residue-off-plastic-no-fuss-method.html

Here's a post that might help https://removeandreplace.com/2015/01/10/20-methods-to-remove-sticky-adhesive-goo-gunk-from-various-surfaces/

A razor blade would definitely work with this one.

You can clean it with rubbing alcohol.