I like working both with undyed and dyed wool, as each of the materials hassome certain strong points. For instance, undyed wool gives clothes a very natural rustic look; its texture is smoother and shinier for it's not been damaged with chemicals.
(Above is the pillowcase, or pillow cover, made from undyed British wool and pure undyed fibres... I'll write some more about pillows in the next posting).
However, if you use only pure wool, you don't have a wide enough range of colours. Dyed wool, on the other hand, even though it sometimes feels too dried up when working with it, which doesn't affect the quality of the final product though, has one huge advantage: it offers a whole range of bold colours. For example: