Vallejo Polyurethane Satin Varnish - Review I just thought I'd mention this and give a quick review because I reckon it's a pretty good product.
It's a bit confusing (or at least I was confused) because Vallejo make something they call "Satin Varnish" which is different to "Polyurethane Satin Varnish" and when people are discussing them they usually don't make the distinction. I have found the latter to be pretty awesome, while the former has been a bit "meh" for me. I thin it with about 30-40% vallejo
AB thinner to 60-70% varnish. Apparently the less you thin it the better, but I found that to be a good ratio for getting a smooth coat, the ratio will obviously depend on your own airbrush. Spray it pretty thin and avoid letting it pool. It says to wait a few hours between coats but I was lazy and only waited a few minutes and it came out really well.
It's a really nice satin
IMO. Most satins tend either toward the matte side (like army painter's spray) or too glossy. But this stuff gives a pretty natural sheen which I think works well. If you find that your current varnish dulls out your model too much, this stuff will probably give you something closer to what your paints look like prior to varnishing.
Just make sure you shake the hell out of it before you use it. When you buy it there'll probably be a blob of white stuff at the bottom, this is the matting agent that gives it a satin finish rather than a gloss finish. I actually had to take the cap off and give it a stir to get it mixed in properly. I imagine that's just because its been sitting on the shelf for a while, hopefully next time just a few shakes will be good.
Just thought I'd give this quick review because at the moment it's my favourite satin varnish and I found it a bit confusing how Vallejo have 2 different products both called satin

I'm impressed how smooth and natural it came out on a WW2 plane I just sprayed (lots of big surfaces which show up flaws and rough finishes!).
When I finish the model I tested it on I might post some pics (still need to finish off the undercarriage and touch up the canopy!).