Hey there. Hope this helps...
Two things before going any further though:
1. If two surfaces are alike in real life (e.g. skin and rubber), then they will have similar values.
2. Micro textures might not be worth drawing unless you have a closeup shot.
So I think you should forget about textures for now and focus more on values and colors. Skin, being a semi-transparent and semi-glossy surface, has numerous ways of transmitting light/color to our eyes. Rubber, being a semi-glossy but opaque surface, only has two ways of transmitting light/color to our eyes. In the end, the difference between them is mainly color!
It would be a hellova task to explain skin rendering in this thread. So here's a link that I found, and maybe there are others out there, even on this forum perhaps.
http://www.imaginefx.com/02287754333...fect-skin.html
To render any kind of material, including a rubbery suit, you will want to understand the terms "diffuse highlight" (a.k.a. midtone) and "specular highlight" (a.k.a. highlight). Those are the two that control the shininess of all materials. I found it really hard to get any related links, but here are some related threads from this forum.
http://www.conceptart.org/forums/sho...ffuse+specular
http://www.conceptart.org/forums/sho...ffuse+specular
As for shading with white and black, you
can use semi-transparent white to create highlights, just don't create midtones using white. You can also use black for shading extremely dark corners and small crevasses and whatnot (adds depth and contrast), but definitely don't use it to darken midtones like you're doing now.
cheers
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