After the excitement of successfully dyeing raffia with tea and getting a lovely colour, I raided the pantry and threw caution to the wind. Instead of testing out the sumac I found lurking with the spices on a small piece of raffia like I did for the tea, I threw it all into a bowl with boiling water and waited to see some lovely new colours. I'm still waiting!
I think the sumac I used was the dried berries. I have a feeling I should have boiled them in a saucepan for a couple of hours to extract the dye before straining and then adding the raffia. Maybe next time?