This soft, oily crayon type medium adheres very well to the surface of your model, either as greasy layer or in clumps. As such it's great for creating mud effects. But it's not exactly subtle, for more even semi-opaque dust effects I have been using powder pigments.
But getting powders to stick to a surface means you have to add some form of binder (or fix the pigment using a spray varnish).
|Powder pigments - whether specialist makes like Vallejo or Humbrol or my cheap|
variation using artists chalks - require a fixing agent to adhere the medium permanently.
This medium has the consistency of powder but incorporates a very mild binder so that it sticks to the surface to which you apply it. It isn't oily - like the weathering stick medium - and can be brushed on delicately (like a dust) or applied a little thicker (like a cream).
In fact, this medium reminded me of something...
I had shown the Tamiya set to my daughter and she agreed that it did look like eyeshadow (or cosmetic powder/cream of some sort). I'm sure it's not, but the similarity in texture was hard to ignore, so I popped into Boots and picked up a box of very cheap eyeshadow (£2.99).
For my £2.99 I got a set of 6 eyeshadow colours (as opposed to just the 3 in the Tamiya weathering set). However, the very first ting I noticed were that a couple of these were vaguely 'metallic' or glittery!
Another quick chat with my daughter informed me that you can get matt eyeshadow, so that's something to be aware of if you decide to try this out for yourself. I tried out the colours that were matt(ish) on my 37 Chevrolet model, and got some reasonable results.
I'd say that eyeshadow, then, is halfway between pigment powders and the Tamiya weathering medium. It's actually quite nice to use, just having that slight adherence that powders only bearly have (without adding a binder or fixing agent, powders tend to wipe off as easily as they go on).
Eyeshadow can 'smear', being a tiny bit oily. But they are a little more subtle or translucent than Tamiya's weathering 'cream' (sorry - I'm struggling here to describe the various mediums precisely).
So...Is Tamiya's Weathering Master Drybrush Effect set just expensive eyeshadow? No. It's subtle but the levels of binding and translucency are different and the Tamiya product is obviously designed with modelling specifically in mind (as it should be).
But...Eyeshadow is an interesting medium in its own right and does offer some unique properties that compliment you other weathering mediums. It's all a sliding scale and depends on how 'sticky' and how translucent and how much you want the medium to spread, but eyeshadow will be a part of my weathering toolbox from now on.
...Oh...And one more advantage of eyeshadow, when you compare it to Tamiya's set. You do get a lot more bang for your bucks...