The problem of potentially damaging a pallet layer that is gripped by clamps of a depalletizing tool is solved i) by detecting the real position of the layer using a pad on the tool that is movable with the clamps towards the pallet layer and whose detected stopping position determines the real position of the layer, and ii) while the layer is gripped by the clamp, by inserting under the layer curtains; the pressure on the layer by the clamps being adapted to the ease to go underneath the layer.