Fillers, Washes, Pigments

Filters:thinned paint 90-10% hand brushed on evenly,used to subtly change the tone of the basecoat

Washes:thinned paint 90-10%,used to impart an overall grimy look,also allowed to accumulate in corners or over surface detail to simulate dirty grime and hilight.

Pigments:are dried paint particles,may be brushed on dry to impart dustiness,or mixed with diffrent mediums to be used for diffrent weathering effects like mud.

There is also "dry brushing," a technique that seems to be going out of favor. It is similar in effect to dry pigments.  I like it (dry brushing) because I can use my existing paints and do not have to by dry pigments, just use existing paints of the right color.

Also realize that these techniques are really an "art", achieved by repeated trial and error.  A really good weathering job takes a lot of experience, and is easy to overdo.  So if I build a nice, expensive model, I usually leave it "factory fresh", rather than risk messing it up by weathering.  I'm talking about aircraft here.  With armour, of course, there's no such thing as "too dirty."

Then there are ships.  Warships in peacetime are kept pretty clean, but during war with continuous action they get pretty dirty.  Merchant ships tend to get really cruddy.  Lots of rust! Cruise liners stay clean but boy the cargo ships make great weathering material!

Thanks for the help

is there any order which these should be applied?

A member on another site recommend this to me and I found it to be very helpful

missing-lynx.com/rareworld.htm