The juice from blueberries can be used as a wood or clothing dye. Make sure you get it right the first time because there is no correcting of mistakes. Rori has used this dying technique for several items with terrific (and permanent) results. For example, her baby doll. It is now a beauitful shade of purpley blue, head to toe. Despite me trying to correct the dye job in the washing machine, her baby is still purple. When blueberries are used to dye fingers, nails and lips it is also very effective although slightly less permanent with effects lasting only a week or two. If smeared onto unfinished wood it produces a gorgeous swirling blue/purple that absolutely will not fade no matter what you do to it.
I should find a way to market this dye.