Acrylic gouache article

[Vermis]

I wrote a wee thing about testing acrylic gouache paint and posted it up at Dakka. I hope it pleases, doesn't preach to the choir, etc.

http://www.dakkadakka.com/wiki/en/Testing_Acrylic_Gouache_Paint

Teaser pics:

[Zardoz]

Interesting and very useful. Does gouache have good adherence to the primer coat and can it be effectively sealed with a varnish layer?

I've looked at gouache in the past but I've never quite gotten around to doing serious experiments with it.

[Vermis]

Ta.

I was going to chuckle and reassure you that this stuff is regular ol' waterproof acrylic polymer emulsion with added gouache-like qualities, but you made me think about the chalk(like) ingredient in the Turner paint. So I got a brush and a jar of water and lightly scrubbed at the test minis.
The Vallejo paints were fine, as expected with very little (if any) filler. The Turner red paint stained the water on the brush a little, but there was no appreciable damage to the paint on the model. The Turner grey paint, though... The black primer started showing through before too long. Maybe not surprising given the large mount of chalk or whatever, but my heart sank to see it!

So, the Turner acryl gouache is still a little vulnerable to re-wetting. For the less chalky colours like the red, I'd say the effect is so negligible that you could go ahead and treat it like regular acrylic paint. Even the grey is probably fine, as long as you're not dunking it in water and actively scrubbing it for a minute. But don't quote me.
As for sealing it, I'll pull out a couple of pots now.

(Thanks though, Zardoz! Important points. Kicking myself that I didn't think of them.)

Edit: now I find the Turner stuff rubs off a bit more easily, too. (see avatar to the left for reaction) Although, that's with a good rub with a fingertip, and even the level of sealing from a thinned-down GW wash seems to help it stick better. I hope that a bog-standard acrylic varnish would sort that out.