Thank you SCH.
I am not an expert of varnishing, I only vanished 2 paper models of mine. What I did was not to spray directly on the model. It was more like a rain and the drops (as a mist) have fallen on the paper. After 4 layers I was bored to wait so long, so I left it like this:
#77
They are not so shiny but protected and the model is not damaged.
I should put more layers on the I think.
Cheers