Abstract: In flow presses for the production and processing of leather, especially in sammying (drying) machines, the need exists for a preliminary effective stretching and widening of the leather to prevent the forming of creases. In a flow press with a pair of pressing rolls (W1, W2), there is arranged for this purpose in the zone of the entrance wedge (EZ) of the rolls, a stretching device (ARV) acting transverse to the flow direction (P1) of the leather, which is adjustable between an open position (OST) permitting introduction of the leather, and a working position (AST) with stretching tools (RW1, RW2) acting on the leather. This permits a perfect introduction of the leather, with visual control and with possibilities of correction. The slight distance attainable between the end section (EA) of the stretching tool and the roll pressing zone (PRZ), especially with non-rotating plate-form stretching tools, favors the suppression of creases in the pressing process.