I have a light tarp from Campmor in an unfinished 9'x9' size with grommets and paracord tiedowns. The tarp easily fits in the map compartment of my german army daypack or the game pocket of my Filson coat. I will never forget a Sierra Club hike that went wrong with a hiker suffering a broken leg and weather moving in. We made a cellcall for assistance and then people started trying to create useable shelter out of two ponchos and some assorted space blankets. I looked like felix the cat producing a hotel from his hat.