Humbrol Matt Varnish Over Acrylic?

Would suggest sealing with Future, apply decals, Matt coat with Polly Scale clear flat - much safer. I have not used the Humbrol product but if it is a true varnish then it may cause severe damage to those underlying paints, you could have decal damage, paint wrinkles or cracks. Order of paints should always be:
Lacquers
Enamels
Acrylics

Humbrol matt varnish will be OK over acrylic paint. I'd suggest you add your decals before drybrushing/weathering, as this allows for the markings to 'fade' into the color scheme. Swanny's suggestion of putting a coat of Future in-between is a good one, though from my experience with Humbrol paints, it's not so much for the benefit of the underlaying paint, but more for having a smoother surface onto which you place the decals. This will diminish the risks of silvering. Then spray on your varnish, then weather.

Thanks!

The kit is the new Polar Lights NX-01 so don't know if drybrushing
after decalling is possible. Will think about it though.

James

James, if the Humbrol product you are refering to is "Mattcote" it will be fine over Future. I have used it in that order with no problems. Just make sure you leave the Future to cure for a couple of days and stir the Mattcote really well before use. I usually thin to 2 parts Mattcote to 1 part Humbrol thinner. For me the 3 keys to success here have been;
1.Plenty of drying time for the Future.
2. Stir the Humbrol product really well, (To disperse all the white matting agent).
3. Just spray enough Mattcote until you have the Matt effect, then stop. If you keep spraying more and more on, you will just get a white chalky haze.

Cheers...Snowy.

Be aware that Humbrol have recently changed the formula for their aerosol matt varnish, and there have been many reports (not least on the Airfix website forum) of people having problems with it, even over cured Future. Stick with Mattcote, appropriately thinned, is my advice.

And James, you would surely weather after the application of decals and varnish! Pristine national markings over weathered paintwork has to look wrong, nicht war?

Chris

Sorry if my post was confusing, as Chris points out steer clear of the aerosol product for what you are doing. In my post I am refering only to the product called "Mattcote" in the little jar which you airbrush on.

Cheers...Snowy