teal dye extract

These are the lovely deep colours from a dyeing session in the slow cooker using DT Crafts teal dye extract .The darker shades had alum as a mordant, the lighter none at all and there are still some drying which have had iron as a mordant.I have no idea what the plant is that is used to create the extract and before I teach any students to use this, I really do need to know, as I like to be as earth friendly as possible.My next step is to use the extracts for thermofax screen printing on my felt, so more photos of that when I have time to do some more work-real work ,I mean, not Christmas shopping or reorganising the workroom, which is so badly needed.