Included in my travels in Thailand was a trip to a cottage industry where they dyed fabric with natural indigo. They actually grew the indigo and processed it into the dye. The dye was mixed with water and possibly some setting agent -- I don't recall that any was mentioned.
The next process was printing with hot wax using carved wooden block prints. The wax is melted and kept hot in vats over a wood fire. We chose a block print from the pile on the table, dipped it in the hot wax, and stamped the white fabric.