24 (2x12) 180gsm art Colouring sheets of superior acid-free drawing paper, printed with exceptional designs in very light lines; each design is included twice, so that you can either create variations or use one for testing and the other as the final artwork.. 24 (2x12) 180gsm art Colouring sheets of superior acid-free drawing paper, printed with exceptional designs in very light lines; each design is included twice, so that you can either create variations or use one for testing and the other as the final artwork.