My recipe is pretty simple.
Toss a bunch of black walnuts into a 5 gallon bucket and fill it half way with water. Wait a while - a week, two weeks, what ever. Come back, it's done. It can then be thinned with water to lighten it. The stuff will stain your skin dark and it will stay that way a long time. Don't ask me how i know that. :shocked2: :idunno:
Green walnuts may make a lighter, yellower stain. Does the same thing to your hands. :shake:
Pecans work too.
I used to cane chairs and stained half the caning to get a nice herringbone pattern.
Some others on here may have more scientific methods adding, salts, alcohol, chemical binders, etc. I never bothered when nuts and rain did the trick. Careful when it splashes, did I mention it stains stuff a long time? :shocked2: :redface:
Steve