Hi,
I usually work with 3 - a liner, a round shader and a mag - but Daz is right, it's good to have a back up as the machines tend to get a carbon build up over a couple of hours etc n I find if it's a big tat, I'm having to stop and tweak them
hi Brian, you can get away with two, a liner and another one for colour, and then you will need to adjust your colour machine to do your shading, in fact you should be doing your shading before you do the colouring but you get the idea, your liner normally has a shorter spring on it and you can use smaller coils,8-10 turns and your colour has a longer spring and bigger coils 10-14 turns.