Hardekool sanded to 320 grit, and finished off with a coat of wood cream. Treat as and when required with a suitable medium of your choice or let it go 'all natural' getting wet is not the problem, drying out too much is, so use it often. This brush is fitted with a 20 mm Silvertip synthetic knot that dries out quick, the brush is small and short to fit into a vintage travel tube, so a great travel buddy indeed! The dense wood brush weighs in at a mere 33 grams, stands 80 mm high, with a knot loft set at a 51 mm loft.