Letraset Pro Marker Sketching Set, Twin-Tip, 10-Pack The ProMarker Sketching Set gives the effect of traditional sketching media with the convenience of a marker ProMarkers allow you to easily overlay and blend colors to create shade and tone; twin tips offer a fine bullet tip for details and a wider tip for large areas Alcohol based, quick drying, and non-toxic This set includes 10 markers and a fine line pen for sketching and outline Conforms to ASTM D4236