Varnish Sharpie I Have A Pair Of Canvas Vans That I Have Drawn On. What Would Be A Good Sealant For Them?

I have a pair of canvas vans that I have drawn on. What would be a good sealant for them? - varnish sharpie

I tried to scotch-guard, but led to only run the Sharpie ink. I thought of clear nail polish, but the use of crack cocaine .. Has anyone concrete proposals, like a kind of varnish or lacquer are tested (preferably)? Thank you!