Bushwalk Australia

To keep my sleeping bag clean I always use a StS liner. I use a bivy frequently, ID Bugaboo/OR Alpine or Highland, but using a liner/sleeping bag/bivy together can get fiddley, awkward and twisted up esp when first getting in. I'm pondering using a quilt but a liner with a quilt seems to defeat the non restrictive purpose of a quilt. I can use a fitted sheet on a thermarest pad to keep it clean but how do any quilt users here protect their quilts from dirt, body oils etc

Gday

I've taken my older silk liner, cut it along both seams length ways to remove the bottom. I then attached a piece of light weight polar fleece to create a footbox on the bottom section (as I use a hammock and this helps with insulation under my feet). However for your bivy use simply cut down both sides to roughly where your knees would be then across to make quilt shaped liner. Then just tidy up the edges on the sewing machine if needed Works a treat and I don't get in a tangle. Nice too on a warm night as I throw the quilt off and have my silk liner on

I have a 4 degree quilt I use in a single walled tent in warmer (non winter) weather. I always use my silk liner with it to protect it, and move around a lot in my sleep. I do find it a little restrictive, mostly in the legs as I normally keep my arms out of the liner. Its not really a big issue or deal breaker for me and so much better than a coffin shaped bag.
I don't use a bivy so cannot comment on how the system would work with the extra layer.