I´ve been reading a lot about dyeing with blueberries lately. You often read, that the colour is not light fast... but a few days ago, I read somewhere on the internet, that people here on Iceland used to get a blue dye from a special type of blueberries so I decided to try it out. I used some blueberries my mother gave me last week... they were getting quite old and I was hoping that this fact could be good for my dyeing-results. I used alum and tartar as a mordant and cooked the wool together with the blueberries for an hour and then left it to cool off over night. The result is AMAZING and I´m really hoping the colour stays this way!
I decided to conduct the following experiment with this yarn: leave it in a sunny window for a week or two and see if the colour changes... I´ll keep you posted!