Manner of writing and stamping instruments

(1) An instrument written upon stamped material shall be so written, and an instrument partly or wholly written before being stamped shall be so stamped, that the stamp appears on the face of the instrument, and cannot be used for or applied to another instrument written upon the same piece of material. (2) If more than one instrument is written upon the same piece of material, each instrument shall be separately and distinctly stamped with the duty with which it is chargeable.