US Patent 11931806 Powder based 3D printing

In one example, a memory having instructions thereon that when executed cause a 3D printing system to repeatedly form each of multiple successive layers of powdered build material on a platform and apply a functional agent to build material in each layer, create a pressure difference across a thickness of build material on the platform, and increase the pressure difference over an extent of build material on the platform as the build material on the platform gets thicker.