Full screen, does it exist?

“No. The term « total screen » is prohibited for sunscreens, because none, even with a high SPF, can block 100% of UV rays.

Note: SPF 15 blocks 93% of UVB, SPF 50 blocks 98%

Also read:

Diet and tanning, is there a link?
Self-tanner, how does it work?
Monoi, its benefits!“