I have a question about varnish. Should I get spray varnish or liquid varnish? Spray is more expensive, but it seems easier to apply? Does a 250ml liquid bottle or a 400ml spray one last more? I draw with acrylics on canvasses, if that makes any difference. So far I've been varnishing only some of my paintings with a liquid matt varnish, but I'll get gloss this time since I don't really like the milky effect my matt has... Any thoughts? Thanks