With my successful willow bark experience, I revisited Sycamore bark. I think that the dye material in bark requires a longer process…more heat, more time, more soaking. More time than leaves.
Sycamore is supposed to give a red dye material. So, I foraged more bark. (From the ground, not from the tree.) Then, I soaked it and heated for a day. I used both treated and untreated fabric.
The treated fabric gave a light tan. To test for tannin, I painted both with ferrous sulfate. There wasn’t enough dark color to indicate tannin. Maybe the bark would give more color if given more time. I’ll keep enjoying the look of my local sycamore tree!