We use the blue closed cell foam for this. WE don't have to inflate it every time we use it....and we stick it into the bungie cord on the outside of our pack, so it is always available for a rest stop, lunch, or even taking off our shoes to ford a stream. They also serve as part of our pillow, and we've been know to use them to create a windshield for our stove, too.
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Check our our website: http://www.backpackthesierra.com/

Or just read a good mystery novel set in the Sierra; https://www.amazon.com/Danger-Falling-Rocks-Paul-Wagner/dp/0984884963