Non metallic metal, usually shortened to NMM, is the technique of painting something to look like metal using ordinary matt colours rather than metallic paint. Instead of relying on real flakes to catch real light, the painter draws the reflections: the bright highlight, the dark shadow and the sharp transition between them are all painted in place, and they stay where they were put whatever angle the model is viewed from.
Why paint metal rather than use metallic paint
Metallic paint contains flakes that catch light, which works beautifully in the hand and photographs poorly, because a camera flattens the shifting sparkle into a dull grey. NMM stays consistent from every angle and under every light, which is why display and competition painters use it and why it dominates the photographs people learn from. The trade is enormous: metallic paint gives a convincing result in one coat, and NMM gold or NMM steel is several hours of careful placement per surface.
How NMM gold and NMM steel differ
Both work by exaggerating contrast far beyond what the eye sees, because polished metal reflects its surroundings rather than diffusing light, so it has near-white highlights next to near-black shadows with a very short transition. NMM steel is built from cool greys and gets its character from a sharp horizon line and a bright sky reflection. NMM gold uses a warmer ramp running from a dark brown through mid-tones to a pale yellow and finally white, and the temptation to stop before the extremes is what makes an attempt look like yellow cloth rather than gold.
The same thinking paints lightning
Lightning painting, and object source lighting generally, is NMM's logic applied to a light source on the model: you decide where the light is, then paint what it would illuminate, brightening surfaces facing it and leaving those behind an obstruction dark. Both techniques are really the same skill, which is deciding on a light direction and committing to it everywhere. Painters who find NMM hard usually find it hard for that reason rather than for any difficulty in brush control.
Questions people ask about non metallic metal
What is non metallic metal?
Painting something to look like metal using ordinary matt colours, with the highlights and reflections painted in place rather than produced by metallic flakes.
Is NMM better than metallic paint?
Not better, different. NMM looks consistent from every angle and photographs well; metallic paint gives a convincing result in one coat and looks excellent in the hand.
Why does my NMM gold look like yellow cloth?
Almost always too little contrast. Polished metal needs near-white highlights against near-black shadows with a short transition, and stopping short of both extremes reads as fabric.