The 4600 Textile Pen is suitable for precise designs on many light-colored, chemically untreated fabrics such as cotton, silk and linen, as well as on a number of mixed fabrics. Once you have drawn on the material, the applied ink can be made permanent by ironing once (without steam), the textiles can be washed at up to 140 degrees F (60 degrees C). The marker features a 1mm thick round nib. The waterproof ink doesn't run during application, dries fast and is very light-resistant.