: Anyone tried an oil based paint?

: I have tinted ZAR on nylon but it's pretty transparent.

I have. Works just fine, but it seems to take a little longer to cure completely. It's kind of soft until then.
I should add that I don't yet have any long term experience with straight oil paint - we'll see how it goes.

If your tinted ZAR is still transparent, add more tint. The times I did it it came out pretty opaque.