by:
Exploring Parks
Depending on your sleeping bag type, you might save more space by stuffing it directly into the storage bag instead of rolling it.
Usually mummy vs. rectangular sleeping bags will determine if you need to roll or stuff your sleeping bag for a smaller pack size
Rectangular sleeping bags usually pack better when they are tightly rolled up instead of stuffed.
The best way to know if you should roll or stuff your sleeping bag is to test out both ways and decide which packs down better.