I have no idea how to even ask this question, so I apologize if I make zero sense. I tried to search the forums, but I have never gotten along well with the search function on this website (it hates me, I swear).

So, if I have a completed drawing that I like, but it's on crappy paper (like an old sketchbook page or something), is there a way to attach it to a quality surface so that it can be painted over (with oils or maybe acrylics)? I thought maybe if I glued it to a wood or masonite surface, and covered it with some clear coating or heavy-duty sealant first then maybe it would work...

I've painted over sketches before (just for practice, nothing serious), and it looks lovely for a few weeks but then the oil starts seeping into the paper and it looks like I've covered the page in lard. Would some strong coats of sealant prevent this, or will the sketch paper under the paint always eventually be destroyed?