Here's how I prepare my paper for oil painting. It's a cheap way to ensure you've always got a lot of surfaces to paint on. I've also found it helpful to work on a surface which you're not too precious with. Paper is great in this respect and as long as you cover it completely with medium or gesso, it should remain archival for many centuries. I use three hundred pound cold press paper so it doesn't wrinkle when I paint. The medium is Acrylic, and I've found this fine for working with oils on top, although occasionally it's too slick so I rough it up with some fine grade sandpaper.