I've been keen to dye fabric with oak bark for years, having learnt that the bark is full of tannin. For centuries it was extracted and used to tan hides. Up until the early part of the 20th century it was used widely to produce a strong yellow dye. (I've learnt so much from Jenny Dean's Wild Colour, which is the most thumbed book in my house!).
I love the wide range of yellows we can get with natural dyes, using onion skin, dried buddleia, golden rod, tansy, and more. I was keen to find out what yellow oak bark gives us.
Living in the Forest of Dean, I'd thought of gathering fallen bark on my walks, and making a dye bath from it. I haven't made the time for that, I bought oak bark from a supplier.
I put the bark chips and some fabric and thread in my dye pan and simmered them for less than an hour. Just a small amount, to see what colour it gives before dyeing larger pieces.
The photo doesn't really show the colour well. It's a gorgeous brownish yellow.
I'm planning to continue using the dye bath, maybe add some onion skins, or madder maybe, to get a range of tones.