True Metallics
or 'Metallic metallics using metallic paints'

This is my tutorial on how to paint plate armour using metallic paints. Anti-NMM if you like... *grins*
Click on the thumbnails for larger images.

OK, stage one. Nice and easy - Add water to GW's Chainmail paint and block in all of the metallic areas. Do not worry about blacklining or drybrushing with this technique as the depth is created by the use of layered ink washes.
Mix up Black and Brown ink in approximately 70:30, black:brown ratio, and dilute to taste (aka add water). Wash this all over the metallic areas blocked out in stage one. You need to load the brush quite heavily with this ink mix to allow it to flow over the armour. However, do not allow the ink to pool as you will get 'tide marks' where the ink dries.
Layer more and more of this ink wash over the armour plates, building up darker areas where they overlap or where you would expect shadows to fall. Again, it is important to keep these layers thin to prevent pooling. Finally, wash black ink between plates for greater definition.
Edge the plates with chainmail to increase the contrast between the shadows and highlights. This makes the armour shine. Depending on 'who' is wearing the armour, this is where you can really define the quality of the metal. This example is an Orc from Reaper's Warlord line and so I have kept it quite dark and rather dirty.
To bring the colours together, I would wash over a very thin coat of the brown/black inkwash over all the armour again. This is also the stage where I would add particular 'weathering' streaks of neat black and brown ink to create the look or worn and badly kept armour. I then very finely edged the armour one final time with chainmail.

There we go, metallic steel done properly, without any grey paint in sight! *winks*