Just finished a PKII and was using some of the MIG pigment techniques. (I was using Doc Martin and Tamiya products: got some MIG stuff inbound.) The kit ended up failing far less dramatically than normal. I was actually rather pleased with the grunge, dust and dirt I had mottled into the Panzer grey top. (The hull was properly mudded. Looked okay I think.) Anyway, I’ve grown accustomed to sealing a kit at the end and put some Tamiya Flat Clear on to finish the kit. Ouch, but all of those subtle pigments simply melded into each other - not at all what I wanted. So I put them back on and left things as it is. However, an unsealed kit has got to be vulnerable over time to dust etc. Anyway to set this stuff without wrecking the effect it’s intended to produce?
I’ve never used any commercial dust % dirt, just the real stuff and pastels… My understanding is the commercial stuff has an adhesive built-in, but I don’t know how robust the colors are…
But I never seal the pastels at all, since the clear coat would lkely destroy the subtle effects achieved… However, you might try the fixative that artists use to “lock down” pastels, or hairspray… As always though… TEST, TEST, TEST…
Personally, I just redo pastel work if it gets damaged during a routine dusting… It doesn’t happen very often, and usually, the pastels are tough enough to take a dusting or two, using the airbrush and a make-up brush…
I generally use mineral spirits to fix MIG pigments to my models, but I use an acryl base as the mineral spirits would eat right through a lacquer or enamel finish, I have never used any fixative after applying my finally weathering as it justs melts away the finish. I would recommend putting your models in a windowed cabinet to minimise the dust collecting. As of today page 7, very bottom, of the readers gallery you can see my 1/48 Tamiya Sherman that I used pigments and acryl paints.
Well I always apply my pigments in a thinned wash with mineral spirit thinner. It seems like they adhere somewhat tightly to the model- and I don’t notice any adherence difference between pastel powder and,say, mig pigments. I’d just say you should definitely consider storing them in cheap individual cases. I just buy the $7 plastic ones at hobby lobby, and I use the 40% off coupon. The real thing you need to worry about is the unremoveable dust… on a dull surface, some of the dust just doesn’t come off. It can look terrible if your models aren’t protected. Don’t seal your pigments- just put the model in a dust-free environment (display case).
When using pigments I normally wait until last until they are used (if they are being used in a loose, brushed on manner).
I apply my spray of dullcoat to give a nice matt finish then brush my pigments over them when the dullcoat is dry-the matt coat ‘grabs’ the pigment better than any glossy finish ever could.
If you want to put heavy pigments on ie under the hull and behind the roadwheels to replicate accumulated grime/dust etc then I tap small piles of pigment lightly over the area then add drops of either MIG Thinner For Washes, MIG Pigment Fixer or good old Enamel Thinner (on an acrylic painted model) and brush/move the pigments around to get full coverage. When dry they will reappear and you can fine tune from there.