i posted this on another website some time ago but here is my personal killer recipe...
posterman "or any big refillable paint marker"
start with 1/8 griffin "stains surfaces with pours"
1/16 brake fluid "eats paint and saturates ink to make it shine"
1/8 xylene based carbon ink (black) "gives a good opaque black color"
1/16 plumbers dye powder "when it rains it leaves neon green drips"
5/8 marsh red t-grade "makes the whole mix turn blood red, also if buffed leaves a red ghost"
this ink mix is nasty and not recomended for the faint at heart... when tagging leaves a fresh blood red (real dark red) tag, if buffed on plastic leaves a red ghost, cant buff off paint or be painted over unless a pigment stopping primer is used, if buffed with soap and water all you have is a fresh blood red tag with alot of neon green smears and drips...
try it out and go fuck some shit up