Thanks for that. I did not know silkspan was still available. I don't know if silkspan finnishes provides the highest strength to weight ratio. I would have to see the data. Silkspan tends to be thick and porous, taking in a lot of heavy dope. I am not familiar with the different weights or grades of silkspan, and I have not used any of the low odor dope substitutes. I have used silkspan back when I was flying control line aircraft. I have used actual silk, sealed with plasticized dope for flexy B/Gs. Elsewhere, I mentioned that I get the best results using the thinest paper and thinned brush on adhesive, meaning tissue and dope. Mostly I use the tissue on balsa contest gliders. I did cover the stock surface mount fins of a Maxi Alpha with tissue and it has survived flight with E20 and F45 ProJet Motors. I probably would have used silkspan there, if I had any handy.
I think the ongoing discussion of papering fins, is not about what is lightest or best for performance, but what can be done with readily available garbage and common materials.
Another trick I picked up from a glider guy is to apply paint from an airbrush and use water-based paints thinned with alcohol. You can put it on in very thin coats using the airbrush and the alcohol evaporates quickly and helps keep the tissue paper tight.
