Smith uses a mould to form the basic shape of each bird and then spends half a day adding the details of beaks, feathers and feet. Completed birds are burnished with a smooth stone to impart a satiny finish before firing. Black­ening is accomplished by immersing the birds in sawdust, which is heated until it carbonises. Smoke permeates the porous clay, turning it black all the way through. A few birds (notably albatrosses) are left white, and Smith makes the odd dolphin for variety.