Patent attributes
According to one example, there is provided a three-dimensional printing system that comprises first and second build material supports adjacent to opposite sides of a build platform, when installed, a distributor to distribute build material, and a spreader for spreading build material. The three-dimensional printing system also comprises a controller to control the distributor to form a pile of build material before a first side of the build platform, to control the spreader to spread across the build platform and to form a pile of excess build material beyond a second side of the build platform, to control the spreader to move to the other side of the pile of excess build material, and to control the spreader to spread the pile of excess build material across the build platform to form a pile of excess build material on the first side of the build platform.
