A machine (Fig. 2) for producing a saddle-stapled booklet has a trayfor receiving and registering sheets to form a group of sheets. The group of sheets is moved horizontally between the upper edge of a vertically movable folder blade (4) between a pair of parallel, side-by-side rollers (2) to fold the sheets. Continued upward movement of the blade (4) drives the folded group of sheets against a pair of staplers (1,1). The booklet thus produced is rejected laterally by a pair of crease-forming rollers (3) disposed side-by-side and rotatable in parallel vertical axes.