Stuff Sack

I've been searching around for the right supplier for silnylon as I sell more and more tarps.  A really great salesman was kind enough to send me some samples for free so I could play around with them and get a feel for their different types of sil.  So I made some stuff sacks with Ultrasil (red) and Skylite (blue).  Both are nice fabrics with similar applications, and coated both sides.  The weight's were no different from each other, but the skylite feels a little thicker (must be the type of coating).

I plan to seam seal one of each with a thick layer of silicone and give them water tests next. 

A simple stuff sack is pretty easy to build yourself.  Here is the way I do it.  Note: the drawing is for a double ended stuff sack ("black bishop sack"), just sew the bottom closed like the side if you want a standard stuff sack like the ones pictured above.  "Black Bishop" sacks are nice for tarps or hammocks so you can leave the suspension loops hanging out each end - just put one end up, and pull the rest out of the bag on the other end, leaving the bag on the suspension line.

I also like to add a loop of 3/8" gross grain so you can hang it upside down (this way if it's in the rain the opening is down and it won't fill up with water).

A. Cut out your rectangle of cloth - twice as wide (+1") and as tall (+2") as you want the bag to be.

B. Fold corners as shown and roll hem, this gives you a nice finished channel for the draw cord. 

C. Sew the end closed, turn inside out and sew a line parallel to the one you just did, about 3/8" away (this gives a finished edge on the inside so it can't fray).  Add a drawcord and cordlock and you're in business.