The present invention relates to a method of manufacturing tearable
sheets, wherewith each sheet obtains a perfectly smooth tear edge when
torn-off. The method comprises the steps of: punching each sheet
transversely of the fibers of said sheet from a first side of the sheet
to an extend corresponding to a firs portion of the thickness of the
sheet; and punching each sheet transversely of the fibers of said sheet
from a second side of the sheet to an extent corresponding to a second
portion of the thickness of said sheet; wherein the sum of said first
thickness portion and said second thickness portion is smaller than the
thickness of the sheet, and wherein the second punching operation is
performed parallel with the first punching operation but displaced in a
plane parallel with said first and said second sides of the sheet, said
displacement being adapted for tear-off purposes.