KAM plastic snaps are industrial grade so are intended to have a strong closure. The thinner or flimsier the material (even if it's multiple layers of the same thin, flimsy material), the more difficult it will feel to open the snaps. As a result, your fabric may be at risk of tearing.
For that reason, we recommend reinforcing thin, stretchy, or delicate material with a sturdier, non-stretch fabric prior to installing the snap. Size 16 plastic snaps can also be used in lieu of the more common size 20 because they are smaller and have a relatively gentler grip. Do note you should still reinforce with size 16.
If you have already attached your snap to your project, opening and closing the snap several times will help to loosen it just a bit. It's also be suggested by some of our Facebook group members that rubbing wax / beeswax / zipper glide sticks on the snaps can help.