Not being a smart mouth here .. but when did you last change your blade? 3 layers - unless it's really heavy weight - should not be a problem at all. A ruler with something on the back - mine has cork stickers - to keep the ruler from sliding - and a sharp/new blade - should cut 6 layers of regular weight cotton.....tho i usually limit myself to 4 (normal number for twice folded yardage) just for the "it's easier" factor.