The ink is used by itself. If you got a bottle of ink with one of the boxes, you purchased an ink line not a chalk line. I use both, ink is nice for basement remodels/build outs where the lines get stepped on a lot and you forget your hairspray at home.I've got two. The red metal case and the black plastic.
It didn't seem to work very well on rough concrete footers.
I also got a little bottle of dye, I think, that came with one of the lines. Is that an additive to the chalk, or does it get used by itself?