Kolinsky Sable is the best hair available for the manufacture of artist brushes due to being conical in shape, strong in character with a long tapered point and thick belly.
The Series 323 Spotters are a favourite amoungst botanical painters. The shorter tip and thicker belly of the brush creates beautiful petals, stems and such.
The Series 323 work well in watercolours, inks, oils for details, acrylics (mainly for miniature painters) and for botanical painters alike, though they are favoured by watercolourists.