This is a blended carded mix of washed fleece wool.

The fibres used are chosen to give the mix a good loft and recovery. This feature makes it a good stuffing wool as it retains its bounce when compressed.
When used in the process of needle felting it gives a sound base to the work when needled into a body shape. 

With this type of blend made from scoured (washed) fleece there is always some vegetable matter in the fibre.