Why are there sometimes tiny bits of vegetation in some of the merino batts?
This is because it is not currently available any other way. Carbonizing wool, as is done with merino top for example, is expensive and therefore reserved for top quality spinning wools. In the wool industry, short-fiber merino not destined to be yarn isnt put through the carbonization process. However from a feltmaking point of view, this wool is top grade. Its extremely fast-felting and creates a very smooth, professional finish that is desirable for designer clothing. The vegetative bits are quite minor and can easily be brushed out of the surface of the finished felt.