A venerable tending the fire for cooking dye Here are pictures about the natural dyeing process. The monks boil the ironwood tree bark chips for a long time (days). When a drop of dye is dropped in a glass of water, a ball will form and sink to the bottom. At that point, the dye master will empty that batch of dye into containers and then reboil the same chips with fresh water to make more dye. You can do this two or three times before the chips are used up.