Power planers, jointers, and joiners flatten, shape, and slot wood workpieces to prepare them for assembly. Planers shave thin layers of material from wood boards to level them to a uniform thickness and smooth off rough spots. Hand planers handle small jobs and perform detailed work while benchtop and stationary planers support large boards and produce more consistent results with high-volume surfacing jobs. Jointers flatten boards to remove bows, cups, and twists and leave one perfectly flat face with a straight, square edge. They are typically used before planers, which smooth and level the opposing face to match the flat face. Biscuit joiners cut pockets that hold biscuits (small wood discs) to connect and align two wood workpiece edges along hidden, glue-filled joints.