There was no universal method for designing vaulting during the Middle Ages. Design processes could vary considerably from site to site and even vault to vault . Yet despite this, there do appear to be some common principles of vault design which recur throughout our case studies. Drawing was the indispensable tool which medieval designers used to set out their vaults. Though initial designs may have been drawn on a smaller scale, the final design work was usually conducted at 1:1 scale using lines incised into a stone or plaster tracing floor. The plan of the vault would be established first, providing the framework within which the two-dimensional layout of the ribs could be defined. The position and orientation of each rib would be set out using a series of simple geometrical operations, resulting in a pattern of varying complexity. With the vault plan in place, the curvatures of the individual ribs could then be worked out. Starting parameters would be defined and geometrical methods would be selected accordingly, allowing the vault’s three-dimensional form to be built up on a rib-by-rib basis.