How do you use grey wash for tattooing?

In my opinion your going to need to take white and mix a little black in for grey. However there is another technique used by myself and other artists, which is simply diluting the black with purified water. the mix can start at 50/50 but you will find that is very dark still. i have cut black down to 15water 1 part black and achieved a very nice subtle ghosty grey.
Sometimes the grey your looking for can only be created by dilution . The downfall is it takes a somewhat experienced artist to deal with the thinner ink. Mixing with white allows you to retain the same consistency which makes it easier. Again though, it makes a "brighter" grey. Brighter greys can quickly turn a nice black and grey piece into a disaster by not blending AT ALL with traditional black and grey wash style tattooing. Of course you can avoid all this and just buy a 6 pack of grey wash shades at Element tattoo supply. I get alot of stuff from them and they rock. Happy Tattooing!!