As examples of the tarp Montanero mentions, check the price of the 8 x 10 Sil/Nylon Ultralight Tarp at $99.99, weighing all of 13 ounces, versus 8 x 10 urethane coated taffeta nylon tarp at $44.99, weighing 22.5 ounces.

The ultralight tarp lighter, but is it light enough to justify twice the price and does silicone impregnated ripstop nylon make a better shelter than urethane coated taffeta nylon? It's a trade-off of cost and performance -- but how you measure performance? The ultralight hiker may measure performance by weight alone. Another hiker in PNW may measure performance by how well the tarp keeps him dry. Another hiker may decide they're both too expensive.

Me? I bought one of the smaller Sil/Nylon Ultralight Tarps to store in my GHB -- it packs really small and weighs 9 ounces. I also bought a larger urethane coated nylon tarp to actually use, bigger and heavier but I don't carry it. (paracord is your friend)

CampMor nylon tarps