What matt topcoat do you use???

[keeper]

I use brush-on Dullcote Lacquer.

But you can't use it straight on acrylic paint, as it is something of a paint stripper. So I varnish first with a craft spray polyurethane varnish, then apply the dullcote lacquer when this is dry.

[Calimero]

I used Army Painter’s Anti-Shine Matt Varnish for the very first time yesterday and I think it worked really well. It cover well and eliminate the "shinny spots" where magic wash was used. I’ve ordered two cans from North Bay Games & Hobbies and, as far as I can tell, it’s good value for the money.

[Phil Robinson]

Daler Rowney Soluble Matt Varnish for me too, used after recommendation by Orctrader and never looked back.