I have to say I like the opaque acrylic with front side engraving and paint, in some cases.
I do not a use mask, just paint brush, water, finger nail and lint free patches to clean up.
It’s a pain to take a picture of a Black piece !!!
I would need some paint gear and talent to get a sharp background like that.
Shipped. Customer had a smile. All good.
No, I did not seal it.