I made a rock mountain out of lightweight hydrocal its 90 degrees and on a bend.
I tried india ink and liked its effect but was wondering should I add burnt umber pigment to make it look less gray?
Also should I apply a couple of light coats untill I get the effect or should I do one coat premixed to my liking?
Possibly. I would spend some time on a tiny, obliquely viewed section, and try some minor dry-brushing first. Try the Burnt Umber, or a whole grey, maybe some zinc-oxide colour for white hilites, even some tan. This is where the faint heart serves no purpose…any boo-boos can be undone with general grey and more washes, or carve/sand a clean face where the goof is.
IOW, experiment and teach yourself what to do when you face this type of problem.
Just my suggestion. [:)]
Look around the web for photos of rock faces that you like the look of. If you are modelling a specific place see if you can not get some good images of the rock coloring in that area. I like to give my rocks a warmer color and then use the India ink wash to provide shadow effects in recesses. It also helps to tone down the color. Don’t be afraid to try some dry brush with a much lighter color to provide highlights as well. If you can’t find an inconspicuous place to try things, consider making a test rock face to practice on.
This all depends on the rock you are trying to model. Even in the same geographical area, there can be various colors present in or throughout the strata. Most just assume that the rock is a form of gray. Take note of rock cuts and outcroppings as you drive. (Assuming there is something like this near you). You will find that very few are actually gray. Light brown to tan, reddish browns, greens etc all can be seen. My club models New England. Here actual gray granite can be found in the numerous local quarries, however, much of this is also mineral stained to crean/ tan, the shale can be various shades of brown/ red and streaks of green or rust minerals will run through.
I will color the plaster with powdered masonry dyes. Black and brown gives a good base color to start with and chips won’t show. This pic shows gray New England granite. Yellow/ tan and red/ rust along with dry brushing the highlights with a light cream.
This pic the rocks are actually more brown than gray, they still need drybrushing and highlights. The brown castings are just loose, they were just placed along with scenery for last show.
