Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for dispensing toners. In one aspect, a cap and valve assembly is provided including a movable valve assembly, the movable valve assembly having a first position and a second position; a toner path, which when open is configured to allow toner to flow from a toner container to an output aperture; and an air inlet path, which when open is configured to couple an air source to the toner container; where in a first valve assembly position the toner path and the air inlet path are closed, and in a second valve assembly position the toner path aid the air inlet path are open.