From memory I recall he used Whatman watercolor papers. They stopped production a while ago, and I think that the paper they were producing wasn’t like what Turner was using. I’ve heard that a papermaker somewhere in France has been trying to make a paper similar to what Turner used. Turner used a variety of techniques with watercolor. I’ll be getting to that.
As far as oil rotting paper I always think of Degas monoprints on sized paper. As far as I know they’re in allright shape. It’s not something I’ve researched or given thought to. If the paper is sized I wouldn’t think that it would rot the paper, just that the oil would darken over time.
I’m unaware of Turner working on primed paper, although I know it was common practice then. I’ve even seen a Lorenzo Lotto on paper that was in good shape (although who knows if it had been restored). So painting on paper goes back a ways historically. I would think that the Bierstadt was haloing from sketching onto unprimed paper. I’ve seen that before with other artists. And with that kind of sketching I wouldn’t imagine there would be oiling out. But that’s just a best guess.
I’ll see if I come across anything in my research about prepared papers for oil painting. I’m too tired to do any reading now, but I’ll get back to this subject, in relation to Turner as soon as I can.
I wanted to post a list of Constable’s paints just to show the similarity as well as contrast to the new pigments that Turner employed. Both artists were radical for their time period. Constable was also using pigments with little track record. But I don’t think to the extent Turner did. It’s always hard to know exactly they were using. Constable’s paints were left intact when he died suddenly. But unfortunately there was a lot of tampering with what was there, and the remaining inventory isn’t entirely clear.
I’ve done a lot of painting on paper. Generally I glue it down to a panel and use heavier watercolor paper (300 lb). I’ve used any number of different primers after sealing the paper.
According to Joyce Townshend Turner did do some oil sketches directly on paper. She didn’t elaborate on how many he did or their condition. I’ve never seen one of them. A cursory google search brings up that he did oil on paper studies for the Burning of the House of Commons and Lords. Turner was an experimenter throughout his life so it’s unsurprising that he would have been oil painting on paper.