From the 1500s, sets of drawing instruments were provided in portable boxes. The larger and more comprehensive sets in plush lined hardwood inlay boxes with brass medallions are more valuable and collectable. Metal instruments in old drawing sets are made mostly of brass and steel, occasionally silver. After 1850 some were made of German silver or nickel silver (alloy of copper, zinc and nickel) and by 1900 mostly electrum (nickel and copper). Pocket sets from the 1700s and early 1800s are small round to flat canisters often elegantly made in silver, shagreen, shark skin or tortoise shell.