I got my Sea-to-Summit Ultra-Sil Day Pack last year, but have only started using it intensively in the last month of travel. It’s a small backpack made of Cordura ripstop fabric and it folds in on itself, down to about the size of a keychain attachment. It can do this because there are absolutely no rigid structures in the pack – just the shape it takes. The should straps are about an inch and a half wide, but attach to adjustable straps that are a little thinner than your standard shoelace. Not surprisingly, the Ultra-Sil is very light, weighing a mere 2.4 ounces.
When I first started using the Ultra-Sil, I wouldn’t do much more than put an extra layer and some headphones or a book in it. I really didn’t try to push its capacity at all. But on my recent trips, I’ve come to realize how much space is in the Ultra-Sil. Unfolded, the sack has a 20L volume. Just last week I used it to carry my 15″ Macbook Pro in a neoprene case, my iPad, and a Tom Bihn Snake Charmer filled with cords & electronic accessories. The Ultra-Sil held this all and had room a set of gym clothes, too.
One of the biggest challenges when traveling ultralight – be it for work or for pleasure – is having an adequate option for exploring within a location. If you want to travel with just one bag, having another bag stored in your main one is oftentimes a necessity. But bags are not small things. The Ultra-Sil allows me to have a functional day pack without giving up any real space in my main bag. Hell, I can carry it in my pocket if I wanted to.
There are some obvious downsides to using the Ultra-Sil as full-time day pack. First, it has no padding and no structure, so you will feel whatever you pack in it. I haven’t felt discomfort yet, but I’ve pretty much just done clothing or a padded laptop sleeve. I can imagine it becoming inconvenient if you were filling the pack with irregular objects. Second, the Ultra-Sil does not have any external or internal pockets. I usually like having a bottle of water with me when I’m out and about, so I do notice the lack of external pockets. I don’t know that I would use the Ultra-Sil on a long hike, but in the context of walking around a foreign city or bringing my laptop from a hotel to a meeting on a work trip, it works pretty well. That it does so without taking up any meaningful volume of space in my suitcase is a huge plus.
The only other drawback is aesthetic. Since the bag is folded up on itself and then stuffed away, when it is first unpacked the Ultra-Sil can look incredibly wrinkled. The wrinkles relax as the bag is filled, but they seem pretty dramatic at first glance. It doesn’t affect the bags efficacy to hold a lot of stuff and it’s temporary, but I thought it worth noting nonetheless.
Two pictures of a fully-loaded Ultra-Sil are below the fold:
Ultra-Sil with 15″ Macbook Pro in neoprene sleeve, iPad, and Tom Bihn Snake Charmer.