Koh-I-Noor Progresso woodless graphite pencils are high-density pencils with a smooth feel used and loved by professional artists. Made from top quality, highly concentrated pigments, Progresso woodless pencils allow the artist to create dense strokes without the use of a lot of pressure. The pencils are water-resistent, non-toxic and an economical choice for all artists.These solid pencils outlast the standard wood-cased pencils and can be sharpened in any electric or manual pencil sharpener.