Lyra Rembrandt Sketching Pencils Sanguine Oil - The oil-based version does not require fixative and is particularly suitable for impromptu portraits. Lead is a mix of finely milled iron oxide & clay with oils & waxes, resulting in a smooth, dense & pasty core. Unlike the dry version, the oil-based pencil leaves a thick, full-bodied, soft and decisive stroke on white paper, creating a marked contrast between this pencil and the warm tone of the sanguine dry.