Although I'm a big fan of the Granite Gear Uberlight CTF3 DrySack (http://www.granitegearstore.com/uberlight-drysacks-P170C15.aspx) which I discussed in another blog, I wanted to mention a new product that serves the same purpose, is a little cheaper, and is a little bigger. Oh yeah, and it's black.
I purchased the Granite Gear DrySacks to keep my sleeping quilt and clothing dry. In the past, I had used a plastic pack liner, which sometimes I still do, but it is a little cumbersome. The Uberlight DrySacks work great and I like having the ability to segregate some things in one bag and other stuff in another bag. But, sometimes putting items together just doesn't make sense. For example, I've had my quilt get wet several times, but not my warm sleeping clothing. Putting them together wouldn't make sense in this case.
Well, Mountainfitter (http://www.mountainfitter.com) has come up with a similar product being marketed as a DrySack and another as a Pack Liner. I have the Pack Liner which is made of the same material as the Granite Gear DrySack. It is $29 for a 30 liter 18"x 24" 1.98 (56 gram) liner. Seams are taped and it has a roll top. If you're someone who wants to put all the things you need to stay dry in one bag, this is a good option. If not, try the DrySacks which come in several different sizes.
I think my only gripe with these kinds of products as they relate to backpacking (being stuffed into a backpack) is that I wish there was a one-way valve to fine tune how much air to deflate. I like keeping my pack as loose as possible so items like down don't suffer from too much compression. Unfortunately, how tight to compress a dry sack or similar product is a decision that needs to be made up front. By the time it's put in the pack and everything else is added, it may need to be taken out and re-rolled if there isn't enough room. This requires a lot of effort and time. If there was a simple one-way valve, it would give the opportunity to merely reach in the pack as a whole, deflate it more, and push everything else in as desired.
It looks like the manufacturer is offering a 10% discount through June 15th with the coupon code BPLsummer2010 which brings the cost to around $26 for the liner.