Jack, just ribbin' you a bit.
Schogun, the snow effect is basically applied in three easy 'layers' -
The first is a lightly-applied spray from directly above the models with white.
Second, white dry pigment is brush-dusted over each model (maybe less around the engine deck) – then the pigment is locked-in with a coat of clear, flat spray. I usually do an additional dusting of white pigment again, on the top (turret, casmate tops, hull fronts), and once again spray dullcoat over the pigment to permanently fix it to the model(s).
At this point I usually apply a light dusting (lt. rubbing in with a soft brush) of black pigment on the engine decking, gun muzzle, and sometimes with some dark earth pigment swiped across the hatches, and at the crew "climbing" points.
Third and last step, is to white dry-brush across the entire model, all the track links/edges, bogie wheels, all the hull detailing, and especially across the engine grates to pop those details up/out from the darker, pigmented decking.
(I white dry-brush to pop edges and sculpted details with just about all my minis – tanks, figures, boats)
If you've got a good brush for this, like an Army Painter Large Drybrush, it's amazing the subtle highlights you can achieve with just white dry brushing.
A little muddying can be applied along the suspension and track guards, etc. after the white dry brushing was completed, as a final touch.
So, none of these techniques are real precision applications, but quick layers built up over the base camo paint color(s) underneath. Since I've already glued rare-earth magnets to the undersides of my models, or mount my figures on steel bases, the models can be affixed onto a board with a magnet sheet strip on top, for spraying, off-loading, pigmenting, board attachment, spraying, off-loading, etc. – and so doing all this weathering in group "lots" at a time).
Using dry pigments can look as if they're air-brushed on (and almost translucent), and can even be used to apply 'feather' edges for camo stripe patterns.
I do shade and shadow along some details with a lead pencil, and/or as a black pin-wash, to further contrast the item against its background – tools, vision ports, cupola and hatches, and when these raised details are hit with the dry brushing, the darker pencil/wash lines help contrast the details further (pencil graphite turns black when dullcoated).
A decade ago, I decided to find ways to speed up painting my minis, and for getting good enough looks for the tabletop, while achieving higher 'production' numbers for wargaming (wargaming use/numbers being my goal, and not for glossy-page-magazine looks).
Actually, I think the expert methods [advice] of brush-on, layer-style painting has done a 'disservice' for many of us gamers wanting to get minis [not display models] onto the table, so we can start having our gaming fun with them……
These snow-camo models do take longer though, because they essentially have two camo patterns on them (base coat/pattern, and winter application on top). For temperate paint schemes, I still use dry pigments for engine decks, muzzles, and dirty weathering, all topped with white dry brushing.
