made with the highest quality Dupont synthetic blend filaments. They can be suspended in water just like Cling on. The filament is tapered & has been flagged to imitate the natural splint ends of the hog bristle. These brushes are medium/stiff & since they are made with SRT (solid round tapered) filament, they have great response with spring back and bend recovery for the flex. This helps with retaining the natural form & shape of the brush. Exactly what you'd expect from the high end professional paint brushes.