Back beam, warp beam (part of weaving loom).
It usually consists of a length of bamboo covered with cloth that is tied to the wall with the tie-cord. In Yakan weaving the warp is not tied to it but runs over it. The warp is continuous. The beginning and end of the warp threads form loops and are joined by a stick. The whole warp is moved on as the weft progresses. When the weaving is finished, the stick is pulled out to separate the two ends.
When you have finished placing the weaving onto the back beam hang it up on the roof plate.