i just started filling my heavy bag with fabric....do i need to cut the fabric into small pieces or can i just throw in whole pieaces of clothes???
It doesn't matter. If it's in there, it's in there.
But I'd expect it to take a lot of clothes/rags to makes a bag dense enough to be worthwhile. You'd probably be better of spending ten bucks at Home Depot on some sand or other filler, or even cheap towels/blankets from the dollar store.
When you finish the bag, how's about tossing up a picture?