A spray fixative should do it. You can get it at an art supply store. I had a similar thing on glass and it worked great… but for display, not something going in and out of your pocket. Is that the actual phone or a case? Either way if the autograph is important to you its now a display piece.

Came here to say this one. I saw it at a film festival in a theatre… ooof that was a lot. My buddy and I got high and watched Super Troopers afterwards as brain bleach. Didn’t work, still rattled.

Chumbawamba - Tub thumping. I had no idea they’ve always been an anarchist sea shanty band and that song was the outlier and a total piss take. I am here for it.