How do I mix a wash?

Sepia, a dirty dark brown, is a great 'jack-of-all-trade' colour for multi-coloured subjects. You'll find it at artist's stores in tubes, either as an oil, acrylic or watercolor paint. This is good for a slap-it all over wash, which I normally use. For 'selictive' or 'surgery' wash, you can go with specific colors, normaly much darker than your base paint(s)... For instance, over sand, I might use burnt sienna, over olive drab, a very dark green, as well a pure black over grilles, mesh,.. and the like.

ok i think ive got most of what a wash is but what about cammoflage tanks ect like i got one that black olive drab and buff how would you go about washing this

what Moses said, but not explicitly,
is that the paint type of your wash should be DIFFERENT than your base.
so he paints in acrylic an washes w/ oils.

do not try to wash w/ the same type of paint as the base coat unless you shoot the kit w/ future or some kind of gloss / protector coat first.
otherwise the wash, being 95% thinner will remove the paint like nobody's business.

i proved this on a airplane this summer!!

like dj, i use the watercolors now.
i thin w/ tap water and a bit of dish soap.
it gives me no trouble over Tamiya acrylics.

if you are not sure, and even if you are,
test it on scrap styrene or a test body you have laying around.

ed.

Moses got it right. I'd just add that you can also use artist's watercolours, mixed with water, a drop of dishwashing liquid and a drop of vinegar. This wash will go anywhere, onto acrylics or enamels, without damaging the colour beneath. It's also the only wash that's easily removed (if you're not happy with it), by placing the model under a tap...

Acrylic washes are better done with isopropyl alcohol than water, but if you do use water, add dishwashing liquid too to break the water' surface tension.

A wash is basically just very thinned down pigment. You can make a wah using Enamels, Acrylics, Oils, and even pastels. I primarily use Oil piants for my washes because I spray almost exclusively in Acrylics. I thin the Oil paint at about 90-95% thinner and 5-10% paint. I would do this same ratio with enamel and acrylic paints. You want the paint to be almost like a "tinted thinner" as the hobby community would say. The purpose of the wash is to stain the base coat in most repects. I like to apply a wash to the entire model, allowing to settle into all teh nooks an crannie. I then use a pin wash around all raised detail (i.e. nuts, bolts, etc. After you do these steps..the model usually looks like a bloody mess. Dry brushing will then give the wash some releif and allow that detail to really stand out.

I am sure there will be a bunch of other sugggestions.

Cheers

Mo