From Semperfli:

'Using similar techniques as with Nano Silk we extruded thin Polyester strands which were then slightly twisted and had a light amount of wax added to them. The amount of wax added has been specifically applied after consultations with top Professional Fly Tyers.

With the lightly twisted strands this allows the thread to both lay flat and split easier than other threads on the market. Having reviewed the market offerings we also added 12/0 to the range and included Fluorescent colors along with the traditional colours desired.'

-See also 12/0