Winsor & Newton ProMarker Y337 Tulip Yellow is ideal marker for sketching. Lemony and light, ProMarker in Tulip Yellow adds brightness to a composition while retaining an element of calm. It is often used to convey darker areas on brass objects. Twin-tipped, so you may use this marker for detailing and broad color applications as well. The marker is non-toxic and has alcohol- and dye-based inks inside.