While most tanks are manufactured, some fuel tanks are still fabricated by metal craftsmen or hand-made in the case of bladder-style tanks. These include custom and restoration tanks for automotive,aircraft, motorcycles, and even tractors. Construction of fuel tanks follows a series of specific steps. The craftsman generally creates a mockup to determine the accurate size and shape of the tank, usually out of foam board. Next, design issues that affect the structure of the tank are addressed – such as where the outlet, drain, fluid level indicator, seams, and baffles go. Then the craftsmen must determine the thickness, temper and alloy of the sheet he will use to make the tank.