The following features add to the comfort of the sleeping bag. Make sure to check them out if your chosen sleeping bag has any of these.
They are the compartments in the sleeping bag that holds the fillings to keep them evenly distributed. They key feature is essential in keeping the filling of your sleeping bag in place even when in storage.
Left and Right hand Zips
This is an extra feature that can allow you to combine two sleeping bags to make a bigger sleeping mat. This feature may come in handy for couples who travel together or for families with kids.
It would also be good if the zippers have anti-snag feature to keep the fabric from being caught up in the zipper when opening and closing the sleeping bag. If this happens repeatedly, it can damage or even rip the fabric.
Inner and Outer linings
Fine nylon or polyester are commonly used as sleeping bag linings. Also look for sleeping bags that have a draft-blocking feature to keep warm air from escaping. The draft-lock feature are draft tubes that run the length of the bag behind the zipper. The Marmot Trestles 15 have snagless insulated draft tube to keep in more warmth
Outer linings are commonly heavy duty ripstop nylon. Like the Kelty Cosmic 20 Down Sleeping Bag, its outer liner is made of high-quality DWR which shield moisture and prevents it from losing insulation. There are some that use dryloft for its water resistant ability.
A draft collar is placed at the base of the hood and helps to stop body heat from escaping from the bag and keeps out the cold around the neck and shoulders.