The question asks about "stain using black walnut leaves". It is not the leaves, it is the hulls of the nut that contain the staining substance. Note that the recipe below is for a dye for baskets. I suspect that the dye prepared with minimal water would be most suitable for staining skin.
From http://basketmakers.com/topics/ht/htwalnutdye.htm:
How to Make Basket Dye From Walnut Hulls
By Susi Nuss
Walnut hulls can be used in this simple nature craft to create a dye for coloring your baskets a warm brown. This dye can be used on reed baskets and some types of woodsplint baskets. Follow these simple instructions.
Difficulty Level: Average Time Required: 30 minutes
Here's How:
- Gather black walnuts from the ground.
- Choose nuts still in the green hull.
- Place the nuts in an old pillowcase.
- Tie the pillowcase tightly shut with a piece of rope.
- Place the nut-filled pillowcase into a large plastic garbage can.
- Allow the rope to drape over the edge of the can for later retrieval of the nuts.
- Fill with the container with hot water.
- Cover the container.
- Allow to steep several days until the dye achieves the depth of color you prefer.
- Strain any solids out of the dye.
- Dye can be decanted into containers and frozen to keep for later use.
- Add a small amount of white vinegar to the dye to reduce the possibility of mold.
- Wet your materials and immerse them in the dye until they reach the color you desire.
- Dye can be painted or sprayed onto finished baskets.
Tips:
- These directions will work with other types of nuts. Try shagbark hickory or pecan.
- You can shuck the nuts, save the nutmeats for eating and use just the hulls for dye. The green outer hull of the nuts renders the most dyestuff.
