Contributors to this thread:
What's your experience with liners? I have a mummy bag that isn't quite warm enough. It will only be for nights I backpack as I will have a CO 76 tag in 22 or 23 with the plan of having a nice camp (or cabin) for a base and then spike camps for a night or two in more remote spots. Looking for as light as possible but that will be the difference between being almost warm enough and comfortable.
I have been using them for years and have 2 fleece liners (one light weight and one heavyweight) and hardly ever use the heavy one.
Love them. Never leave TH without one. Makes sleeping bag feel warmer and separates you from the damp bag. No brainer. Always makes me gear list no matter how light I go.
I have used a cotton flannel liner for years in my mummies. Best part is that I do not need to clean the bag near as often as without having a liner. Reduces the cold nylon to skin experience, adds warmth and can be used to cover up if the bag is too warm.
I prefer wearing a set of long johns.
I use a silk liner with my quilt. It keeps the quilt cleaner and cuts down on drafts.
My 17 degrees treated Big Agnes down bag was too cold sometimes, so I purchase one of their liners for $90 and that gave me 10 more degrees of comfort. I can use or not use the liner as needed.
But if one is just sleeping on an air mat, this might be the problem that the sleeping bag is too cold as the cold air (during the night) in the mat is making contact to the bag. To solve the cold air mat problem, I place a fold- up foam/rubber mat on top of the air mat and this prevents the cold air in the air mat from reaching the sleeping bag.
My wife took a cotton bed sheet and sewed it into a tube, with one end sewed shut. That’s my liner. It keeps cold nylon off my skin and adds a lot of warmth.
I use a fleece bag liner I bought at Walmart . Have used it for at least 5 years. Many nights I only use the liner with no bag. When severely cold I use it inside my bag. One of the best investments I ever made.
The silk one I use wicks moisture into the bag better than my thin synthetic one and is lighter.
If you can find GI poncho liners they work great and weigh nothing.
If you're backpacking in, the best warmth-for-weight option might be to wear more of the clothes you already have with you. I start with just a t-shirt and socks. If its cooler I add long johns and long sleeve shirt. If that's not enough throw on a wool or down sweater and a stocking cap. If I'm still cold I obviously brought the wrong sleeping bag!
I have a silk liner by Marmot for my Marmot down bag. I can't get used to it, so I just wear a set of Ice Breaker merino top and bottom. Moves with me and slides nicely on the bag so it doesn't get twisted. If it gets colder, I start putting on clothes that I already have with me, which always includes a light down jacket and pants. (Kuiu)
I'm a side sleeper and turn from side to side a couple times in the night. I've tried several different liners and always end up wrapped up in a twist.
Used one for the first time this fall. Amazing. Loved it.
Buy enough fleece material for the bag you want and have a liner sewed. Since pattern/color should not be a concern you can often buy it for bargain prices. My wife has sewed quite a few in the past.
Don't get cotton. You could end up getting wet and that would be bad in cotton.
Jaquomo, you may have just talked me out of a liner as you just described my sleeping pattern to a T. Wondering if the moreno wool long johns isn't a better answer. They would be nice for the first few hours of the morning hunt anyway.
I am totally with Ambush...just start adding clothes you already have along (or likely just not taking them off). They'll be dry when you get up too, even if they start out wet.
The KUIU down zip-off pants and hooded down puffy are great for glassing during the day and adding 20*F at night to the bag comfort rating. They also could be a lifesaver in the pack if you have to spend a night out away from your tent and sleeping bag under your siltarp.
Darrell, I am a side/back/front sleeper too. I twist and turn all night, most nights. I sometimes get a little twisty in my liner, but it's not bad at all and I really like my liner.
Suggestion- if you're going to go with merino wool LJs instead, I recommend the KUIU zip off ones. They are slick as cat snot on a door knob when it warms up and you want to take them off.
Been using a silk liner on many mountain hunts. Tried fleece and other synthetics but for me silk feels much better next to my skin, is very temperature regulatory, and packs down / weighs next to nothing. Wearing extra clothes provides some extra warmth in a pinch but I find a liner works much better for staying warm and comfortable in the bag.
Like said above they work great get one
Check out 'Sea to Summit' bag liners...
they have about 7 of varying weights temp ratings. And they go into detail on specs, for size, and compressed sized etc.