Originally Posted by MTBMaven

Albert, Yes traditional compression sacks have four straps that pull down on the bag and compress the contents. I have found the roll top Sea to Summit and OR bags to be every bit as much of a compression sack without the bulk of a traditional compression sack. There is certainly a technique to it but if done properly it will compress quite a bit (assuming the item you stuff inside compress well) with the added benefits of being very lightweight and watertight.

For this to work well you need to stuff in the contents, press down on the contents (I like to fold over the top of the bag), then roll down the top. If done right the bag has a tendency to not let air bag in. After a roll or two no more air will get as a seal has been made.

I guess I need to make a video of the process next week when I start loading up for our trip over Memorial Day weekend.