TPU Generic Case for iPhone SE v2.  I believe the SE v2 is the iPhone 8, so it should work for that as well, but I have only test fit it to an Iphone SE version 2.  Optimized for no-supports, as with most TPU prints, you may get a minor amount of stringing.  I've made about 12 of these so far and it really only has minor stringing in the inside because the sides of the phone are rounded, so you get a slight overhang.  With how this fits, I kinda doubt it will work with a hard material.  This was designed specifically for TPU.  If you want to add your own graphics that don't go all the way through, I found that if you keep it shallow (around 0.25mm), that it should print without issue.  I printed this on a high temp bed, which gives a matte finish, so for the logo, I found that it was best to create the inset region as a border, so that you get the matte finish on your logo/graphic, and not the overhang, more glossy look.