Fibrepens create a 0.5 mm to 4 mm paintbrush stroke, making them ideal for calligraphy, lettering, and painting with various strokes and mixing colors. They feature a fibre tip and come in 10 colors. The water-based paint produces bright, easily applied colors that can be mixed together. It can be easily washed out of most fabrics by soaking the item in cold water for an hour and then machine washing on a cold setting. Each pen includes a perforated safety cap.