Green Stuff Worlds Gold Series Siberian Kolinsky Brush - Size 0 Green Stuff Worlds range of premium quality Kolinsky brushes, GOLD SERIES. Expertly hand-crafted with a high-quality wooden handle and brass ferrule, only the best parts of Kolinsky Siberian hair have been used in the making of the Gold Series brushes, producing high-end brushes of the finest quality. They stand out from the mid-range in their greater paint load capacity, higher quality, and masterful fine line strokes. These brushes work best with water-based acrylic paints, especially with fine techniques such as washing, blending, and layering. In general, they are recommended for any technique which requires a more diluted medium. We advise against single stroke or dry brushing techniques as these may harm the tip. This type of hair ensures a high absorption of water and paint and excellent elasticity, making it a very technical brush. By nature, natural brushes require more care than synthetic art brushes, as their decay may lead to a loss of firmness and broken hairs. For your kolinsky brushes to last longer we recommend avoiding letting any paint residue to dry in the bristles and shaping them and sharpening the point with our Brush Repair Gel. After painting, let them stand with the bristles pointing upwards to avoid deforming the tips. Well maintained brushes will give you years of use!