EDIT: I may have buried the lead with this question. I do not want to use xray mode because that makes everything transparent. I've been away from Blender for a couple of months and just installed 2.81, having previously considered myself a 2.80 guru. Now I am feeling very embarrassed because I can't figure out how to make my meshes display semi-transparent in the viewport so I can see reference images through them. I don't want to make materials, I just want some meshes to appear transparent without putting everything in xray mode.