After enjoying this hobby for a year now, I have reflected on the incredibly massive amounts of knowledge I have attained to increase my understanding of painting miniatures.
While some skills came to me almost innately, most had to be learned through careful research or by pestering the great artists around me.
Both of these were made possible by using CMoN's forums and articles page.
It did not take long before I feel I had an understanding of NMM. And so I'd like to pay it forward and talk for a minute about NMM and the techniques and recipes that I found work for me. This isn't an SBS, but rather an explanation and/or recipe for NMM gold, bronze, steel, copper, and enchanted colored metal.
Before I begin with the particulars of each metal, some rules apply that are consistent for all metals. Whether the dirtiest copper or the brightest chrome, one must be aware of certain truths.
1. Metals are high in contrast.
This is true in general of all materials when painting small scale models, but it is most true with metal. This is what makes metal appear shiney without having to use gloss or true metallics. Simply observe anything metal in nature to know this is true. The shinier you want an object to be, the higher the contrast (and more use of highlights) there should be.
2. In places, the darkest tone needs to be placed next to the lightest tone.
This usually occurs where two angles meet, especially if the angle causes one side to be obscured by the light source.
Imagine a metal cube as an extreme example of this. One square is painted to be lighter and whiter as one approaches an edge. The edge of the square is pure white, and a different square that touches this edge starts from the edge as pure black and gets lighter as one paints away from the edge. Looking at this apex, one can see pure white right next to pure black. Now imagine this effect on a sword, or a knee pad.
3. Metals must have light edges.
Edges that are touched by light should be highlighted as a very light tone, often close to white. This can be true even of portions of metal that are otherwise in shadow, because the lip of the metal absorbs the light. Edge highlighting is the rule here, but even edge highlighting should be painted as a blended gradient.
4. Metals should have white hot glare points
This also contributes to the appearance of shine. These glare points need to very, very small. They are more effective if they are the same size as the pupil in the miniature's eye. These also appear in locations that are not always already highlighted, or even in shadows.
These are BloodFather's Four Fundamentals of False Metallics. Apply these rules and you will achieve the appearance of metal despite your secret recipes.
BloodFather's Four can be seen on the first example, NMM steel. Notice the black to white on the breastplate, the edge highlighting. The contrast is maximized, from flat black to pure white. This gives it a chrome like finish. The only way to make the metal more reflective would be to use the principles of SENMM, which is for another article altogether. For steel, any dark, middle, and light gray will do. Mix some of these tones together, include black and white, and you'll have at least 8 colors in your gradient. Add nuance to the steel by either gently glazing on a saturated, highly diluted color, or directly mix blue or another color in with your grays.
This metal was the hardest for me to master, because it is easy to make your golds too brown or too yellow. You will see examples of my lack of mastery on my other models not used for this example. However, a desaturated, warm yellowish brown needs to be used as the base color. From here, it is simply a matter of adding more and more VMC ivory (or any whitish) to make the gold brighter. Shadows are obtained by first glazing a highly diluted black into the shadows, and then a purple is glazed selectively into the darkest spots. Citadel's Snakebite Leather was the key for me. Though no longer available, a mix of 2 parts XV88 and 1 part Balor Brown is a good replacement.
This is a fun metal to paint, because the recipe gives such good results. Citadel's Ratskin Flesh is the key here, because of the pink tone it acquires when lightened. Start with an even mix of the RS Flesh and Mournfang Brown (formerly Bestial Brown). As you lighten, take away the BB until you have pure RS. Now, to highlight start adding a white or bone or ivory to the RS, stopping when you have almost pure white for your edges and glare points. Shade with more until pure BB. In the absence of Ratskin Flesh, go buy some Ratskin Flesh. If your LGS has been firebombed, it is acceptable to use Rhinox Hide (formerly Scorched Brown) for a different but effective copper substitute.
My experience with this metal is the most limited for me. Start with Mournfang Brown, shading by adding more and more Rhinox Hide to the base. Highlight by adding a desaturated yellow or ochre type color. I used VGC Bronzed Flesh, which is equivalent to VMC Dark Flesh. Restrict the use of the highlights to small areas on raised or worn surfaces. Verdigris where appropriate. On this dwarf you can see the mix on both the demon head at his groin and his mask.
Finally we have colored metal. I went for a saturated look, so instead of mixing in black and white, I used colors that didn't require any mixing. While the colors aren't specific to any natural metal, following BloodFather's Four gives the armor a metallic quality. Also notice on the spear I simply glazed on a red brown over the NMM steel. This is another way to achieve a more subtle tint to your metals, particularly steel.
Thank you for taking the time to read this explanation.
These are of course learned recipes and skills, so I need to give credit to Sproket for his wonderful blog and WIP here on CMoN. AndyG and TenBall have also provided a ton of inspiration and instruction. I will be happy to answer any PMs requesting assistance or further explanation. God loves the Infantry.