Koh-I-Noor Gioconda Artists' Drawing Chalks Sepia Russet blend easily and are extremely easy to use. They allow you to produce a smooth, beautiful texture. These are mainly intended for use with mechanical pencils. Suitable for black and white artistic drawing, these leads can be used by artists and hobbyists as well. Each lead has a round profile of 5.6 mm diameter and measures 75 mm in length.