The "pigments" are very fine. I mix them with other rock powders to change the overall color and to vary the strata in rocks. I mix the powder colors with white glue and wet water (The correct
ratio is the one that works for you), and just treat it like paint. The powder tends to settle out, so you'll have to stir it with each brush load, but that becomes almost automatic. Another trick is
to occasionally pick up some of the "paint" without stirring it first to vary the colors.
I usually mix several batches at once and vary the pigment to powder ratio to obtain my strata colors, starting with the lighter colors and working my way to the darker shades and especially
shadows.
If it's going to be a forbidding rock face, I may give it an India Ink/alcohol wash first for background, then use something like Gray Granite Powder. The India Ink wash darkens it enough that Black
Pigment usually isn't necessary. At the top of the cliff, I'll mix in some White Pigment and make it thin enough to run down the face. It gives the impression of lime deposits deposited by
runoff.
On flatter surfaces, I've had pretty good luck by painting it with my earth color first, then applying the powder/pigment "paint" after it dries.
Mother Nature's colors and textures are anything but even, so use variety on your layout...
Well, my background is painting miniatures for gaming purposes. So, among other things, I've painted 25/20/15mm buildings.
My friends and I use the "Black Primer Drybrush" method. We used to paint them like most people would normally paint something: base color, details, weathering (washes and drybrushing), etc. Since
we've gone to the drybrush method, things go a lot faster.
Basically, you spray the building in black auto primer, then drybrush the base color on (like stone). Then, you drybrush lighter colors for highlights, darker colors for shadows, drybrush the
appropriate colors for the details (doors, windowframes,etc.), etc. The black in the grooves eliminates the need for a wash.
For paints, we use acrylic craft paints, like what you find at Michaels or Ben Franklin. Delta Ceramcoat, Apple Barrel, Folk Art are good brands, and they're always on sale. $0.59 will get you at
least twice as much paint as you would get in a standard 1/2oz Model Master/Floquil bottle. Plus, you can mix and thin with water; we use our forearms and the back of our hands as pallets while
painting. Color choices are outstanding, it shouldn't be hard to find something that will match whatever color you're looking for. I do have one that's a stone-ish color, but I can't recall the brand
or color at the moment.
Thing is, though, you will get a really grungy, weathered looking building. Not everybody likes that kind of look, they like the "parade ground, like new" look. But from a distance, if done right,
it's very subtle, and in HO scale (or N scale for that matter), it looks good on a layout (or gaming table). With a little practice, you can find a good mix for your look. My first Gothic church was
very dark and foreboding, but I also did a Norman Farmhouse which is very clean looking.
BTW, the biggest building I've ever painted this way was one of those $4.99 toy castles from Toys R Us. I've also started on one of those Fisher Price Adventure Castles, it looks really bad
initially, but once you get further in, it starts to look good.
Kennedy
I have several feet of a rather steep slope (between levels of track; about 6 inches high) that I can't decide how to finish. At the present time half of it is unpainted plaster and the other half
is plaster painted with beige latex paint.
One way is to cover the slope with cast rocks and then stain them. The only other way seems to cover with ground foam and add a few bushes. I can't decide which will look better, or if there are
other options. The steepness of the slope seems to require special treatment to make it look natural.
Spencer in Montana
You could also consider a brick/concrete wall (if it would fit the area)
Tom Luton
It kind of depends on the rest of your scenery. If you're modelling rolling midwest farmland, a rock cut may seem a little out of place. OTOH, in the rockies, it would be totally accurate.
Where I grew up on the Milwaukee Road, there was a cut behind our house that had a slope of almost 70 degrees (which one would think to be well above the "angle of repose" for dirt) that was all
grass covered, so it boils down to, "what looks good for you".
Don Dellmann