Birch bark was one of the first things on my list to gather as we live so close to the woodland and I knew there would be some fallen trees to hand. This does go with a word of warning though... my fallen tree was laying with roots stuck high to the air and had obviously been knocked down in a gale. Safe for taking samples I thought, until the tree decided to take a sample of me! Using a small knife to prise some bark away it slipped and I skinned the pad of my index finger with the blade, just like peeling bark off a tree. Ah karma ! I noticed there were still green leaves on the branches laying half burried in the grass, so I moved on to another piece that was definately dead. The bark came off much easier on that piece.
Once home I started the process of making the pieces a bit smaller before putting them to soak and release their colour.