They are made from various sheep wool, Swaledale, (cream) Herdwick, (mid grey) Suffolk, (light grey/fawn as per illustration above) Jacob Black, (dark brown), Jacob Grey (brown/grey mix). All these are natural colours.
These hats have been worn from the 14th century through to modern times. They are mentioned in Shakespeare’s Henry the V.
The distinctive feature of the hat is the double ribbed headband with a loop. This enables the hat to be worn over the ears or turned back to expose the ears. The loop allows it to be hung from a belt or breastplate. The cap also has a covered wooden button at the centre of the crown. It is useful worn under a helmet for padding or also as a headcover for soldiers or sailors.