If I were doing something like a gasmask using black on a white surface, I would reduce the black until it becomes more grey, and let the white of the surface be my highlights, Let the edges of the black fade towards where you want your highlights to be and as the colour saturation gets less it will give a seamless blend, Darken up the shadows towards a truer black, again letting them fade out naturally where possible, then you'll have black white, and many, many different shades of grey in between. A few white highlights to finish, and you'll have a shed load of depth. It is easier to do this withaout stencilos or frisket etc, as you won't have to worry about crating hard lines. I am not a colour expert, but think I am getting better with it, and I apply the same technique up to a point. I usually start from light to dark, (if you start to dark, then you can't develop natural tones and contrast as you will have nowhere to go) letting any edges fade out naturally where necessary, and again use the white from the paper.. You just have to bear in mind that if using transparents, then when you start adding the next layer it will blend colour with the layer below. So for example spraying red over yellow will become orange (you can use an intercoat to protect the colour below if you don't want it to blend, or use an opaque as that will cover the layer below.) If you spray the yellow close to the red, the two areas where the fades meet will become orange, and suddenly you have an area of colour that seamlessly blends from yellow to orange to red. If you spray the beginning of the yellow lightly, and the end of the red lightly that can be extended to pale yellow, yellow, orange, red, pink. You can also get a lot of colour variation with a single colour, the same way you do with monotone, by the density of colour you use. So it can look like you have used 30 colours, but a lot of the time it's just varying how you blend, and how you build the colour up, as well as mixing colour in the cup. I only use the 3 primary colours in transparents (called detail in Wicked paints) and opaque black and white. I mix everything I need from this, gradually getting darker in more shadowed areas. I have oversimplified it, but that is basically what I do, although as I say I am no expert Lol! The best way to learn is to just try and see what works, you soon see what doesn't work Lol. If you mess up, just paint it all white and start again. Annoying, but not the end of the world. Just have fun and give it a try.
. A few tricks I use when doing monochrome stuff are:
