Thanks dudes, very kind.
Obviously getting the different textures right was key to this guy, so trying to mess about with highlights and get them right was what I concentrated on. The armour was a be-atch and I repainted the helmet slightly because the first time I did it, I made it too symmetrical and it was just a bunch of evenly spaced white streaks. I realised my mistake and stuck some random blobs in here and there and gave it more patches of black to stop it looking too zebra-like. The armour needed blobs of pure black going to white highlights to show it was shiny - the cloak needed more of a gradual blend through greys (without an extreme highlight) to show it was dull, and the arms & legs were somewhere in the middle.
Like I say, this is only going to be added to very slowly, because the paying work comes first, but hopefully it will get a new addition every few months or so.
