Black paint on rock faces.

Regular Elmer's White Glue will work perfectly. I would use a heavier wash and and either load up a brush and start at the top letting it run down or use a spray bottle. The thing about washes is that they deposit very little color and require several applications before you see any effects.

 

 

You may be overthinking it.  I love the leopard spot technique on rocks.  I don't remember thinning out the colors.  I think it was more like dipping a wet brush in the paint.  Don't be afraid to put some color down, then your final wash will be thinned out, but not as watery as you describe it.  The scenic cement works great for adhering ground cover with a spray bottle.   For clump foliage use Elmer's glue, something more substantial.  Keep practicing.  Nobody knows the right way to do something unless he's done it a time or two.

Taylor

IMHO the second method is better for coloring the rocks. I've used diluted Burnt Umber and Yellow to spot the rocks then using SLATE GRAY wash over the entire rock simple with great results.  As for adhering clump foliage to a vertical surface use hot Glue "a little dab will do ya"

Troels Kirk is one of the finest modelers of the current age and he paints the rocks black first then dry brushes the surface colors later.  Check some of his modeling here, it's ON30.  Russ

 

 

http://www.modvid.com.au/html/body_troels_kirk1.html

That 32/1 ratio is way too thin depending on the type of paint your are using. I know that WS video says to do it 32/1 but it didn't work for me either. I tried 16/1 and even 8/1 and put it on with a foam brush. Just remember, black is unforgiving if it's too heavy. Always better to start light and get heavier as needed. Otherwise you just got black.

 

For gluing vertical clumps, you can use a tacky glue or a spray adhesive. 3M spray or the spray that Scenic Express uses.

Also check out Dave Frary's great videos.  Russ

 

https://www.youtube.com/watch?v=TsQ-LU2sFLs

Yes, indeed. There is little question that starting with a black base is the optimal way to achieve the look of deep shadows that most natural mountain scenes require. But for some reason, many people on this list find this fairly obvious advice impossible to accept. Conventional wisdom is not always wise.

I use that method, paint the whole thing flat black or a very dark brownish black first, then come back with the rock colors, etc.  It fills in the crevices and gives some added texture and reality to it.  Troels Kirk had it right on how to do it. 

It's all the same when you follow with a black wash.  It certainly will get into any crevice you want. Or a gray wash, or a yellow, or better yet, a combo of them all.  I have found following the directions with the Woodland Scenics paint set worked great.  Of course, experience by doing and having kind of a feel for it are invaluable.  Don't overthink it.  You can get excellent results by experimenting.

Lighter washes are better to begin with.  You can darken later if you want. Tough to make it lighter again.

Wow, those are great rocks Mike CT.  Excellent look to them!