i've fallen in love with tin. i haven't done much dyeing yet (experimented some last summer and have been doing more in the past couple of weeks). using only natural dyes, i need to add a mordant (a mineral) to help "fix" the dye to the fleece. i've only used alum which tends to brighten the colour but have now discovered tin which is said to "sadden" the colour. this pot of dye is made from onion skins and tin. a wonderful dark pea green. i used some of this yarn in "where the wild things are" - now listed in my etsy shop.