The Winsor & Newton Professional Watercolour Sable Brush Round No.4 is a high-quality brush designed for professional watercolour artists. The brush is made from the finest quality sable hair, which is soft and flexible, allowing for precise control and a smooth, even application of paint. The brush has a round shape and a long handle, making it easy to hold and control. The brush is also durable and resistant to wear and tear, ensuring it will last for many years. The brush is ideal for creating fine details and delicate lines, as well as for blending and shading. It is suitable for use with all types of watercolour paints, and can be used on a variety of surfaces, including paper, canvas, and wood. To use the brush, simply dip it in water and then in the paint, and then apply the paint to the desired surface. To clean the brush, rinse it in warm water and then reshape the bristles before allowing it to dry. The Winsor & Newton Professional Watercolour Sable Brush Round No.4 is an excellent choice for professional watercolour artists who are looking for a high-quality brush that will provide them with precise control and a smooth, even application of paint.