@battle.munky ive never tried store bought shells. Your looking for the outer husk, not the shell surrounding the nut. But that’s just for tree nuts. Lots of other items available at the store....Coffee, Tobacco, tea, almost anything that makes liquid change color will make leather do the same. Some better and more desirable than others. The color you get will depend on amount of time soaking. If I brushed on the dye it’d basically be unnoticeable. With the batch I’m using now I’ve found about 24 hours to be as dark as it’s gonna get.