Ok, I believe it… I’m just greatly relieved that it worked. I did what basically amounts to a charcoal transfer, but using white chalk in place of the charcoal, to transfer the elliptical orbital-paths of the planets onto the painting. I didn’t dare try to freehand them over the top of all those finished bits. My two biggest concerns were that the lines wouldn’t transfer cleanly, which I’m glad to say they did, and that it would be hard to align the transfer with the painting. The alignment worked out better than I had hoped. In fact, the only place I’ll have to make a slight adjustment as I paint over the chalk is the point at which Neptune intersects it’s own orbit. The chalk comes off cleanly with a little linseed oil, so the errant transfer lines shouldn’t be too much of a problem.

Orbital White Chalk Transfer Terra Incognita