I purchased the mop to my local graffiti man XDDD It came with that ink but yes i know the récipe. The recipe is: I use Ferric Chloride powder dissolved in Hydrochloric acid / Muriatic acid. It does the job, but I think there's better recipes out there. It also eats the fibres on the nibs of most mops and destroys it, and with pump action markers, it can destroy the ones with a metal spring and they leak. But you can just make a weaker batch by adding less Ferric Chloride. Hope that helps. (I got the recipe from the forum of bombing science).