Can one tear off perforated towel paper etc on Shabbos?
We do not tear off paper towels from each other on Shabbos. The reason is because it is meleches Koraya (ripping) by tearing them apart. If the person specifically wants to rip it along the perforations, then it is also meleches Michatech (cutting something to size).
O:CH 340-13, M:B 340-41.