Question about oil on glass and paper.

Heyo,

I hope this is the right subreddit. I'm an oil painter normally and with the new year I've been looking to try new things. I want to start painting on glass and paper

When I paint on glass is there anything I can coat the finished work in anything to protect it like varnish? Hopefully something that gives it some luster.

For paper should I treat it like canvas and give it use gesso to prime it? Any suggestions? Also I was going to use some printmaking paper like arches. I feel like painting on paper will be tricky but I'm looking for a new challenge.

Any suggestions or hints would be helpful. Thanks all