An additive manufacturing build material container including: - a reservoir to hold build material; - an outlet structure to allow build material to exit the reservoir through said outlet structure; and - a throughput structure, distinct from said outlet structure, including a throughput opening to allow a gas to enter into the reservoir through said throughput opening, • wherein said throughput opening provides access to build material in and out of said reservoir, • wherein the throughput structure includes a removable filter structure to inhibit access of build material in and out of said reservoir while allowing gas to enter into said reservoir, when said removable filter structure is coupled with the throughput structure, and characterized in that • the removable filter structure includes a support structure and a filter held by the support structure, the removable filter structure allowing for venting of the inside of the reservoir, said removable filter structure being arranged to be selectively coupled to and uncoupled from the reservoir such that: (i) the throughput structure allows build material to be poured out of the reservoir when the removable filter structure is uncoupled from the reservoir; and (ii) the throughput structure retains build material in the reservoir while allowing gas to enter and exit said reservoir when the removable filter structure is coupled to the reservoir. - a reservoir to hold build material; - an outlet structure to allow build material to exit the reservoir through said outlet structure; and - a throughput structure, distinct from said outlet structure, including a throughput opening to allow a gas to enter into the reservoir through said throughput opening, • wherein said throughput opening provides access to build material in and out of said reservoir, • wherein the throughput structure includes a removable filter structure to inhibit access of build material in and out of said reservoir while allowing gas to enter into said reservoir, when said removable filter structure is coupled with the throughput structure, and characterized in that • the removable filter structure includes a support structure and a filter held by the support structure, the removable filter structure allowing for venting of the inside of the reservoir, said removable filter structure being arranged to be selectively coupled to and uncoupled from the reservoir such that: (i) the throughput structure allows build material to be poured out of the reservoir when the removable filter structure is uncoupled from the reservoir; and (ii) the throughput structure retains build material in the reservoir while allowing gas to enter and exit said reservoir when the removable filter structure is coupled to the reservoir. • wherein said throughput opening provides access to build material in and out of said reservoir, • wherein the throughput structure includes a removable filter structure to inhibit access of build material in and out of said reservoir while allowing gas to enter into said reservoir, when said removable filter structure is coupled with the throughput structure, and characterized in that • the removable filter structure includes a support structure and a filter held by the support structure, the removable filter structure allowing for venting of the inside of the reservoir, said removable filter structure being arranged to be selectively coupled to and uncoupled from the reservoir such that: (i) the throughput structure allows build material to be poured out of the reservoir when the removable filter structure is uncoupled from the reservoir; and (ii) the throughput structure retains build material in the reservoir while allowing gas to enter and exit said reservoir when the removable filter structure is coupled to the reservoir. (i) the throughput structure allows build material to be poured out of the reservoir when the removable filter structure is uncoupled from the reservoir; and (ii) the throughput structure retains build material in the reservoir while allowing gas to enter and exit said reservoir when the removable filter structure is coupled to the reservoir.