T-Tech by Tumi Travel Accessories Packable Backpack 

"I just recently received this bag so I can't speak to durability, but there were no reviews so I wanted to add my two cents for other buyers. The best thing about this bag is that it's BIG. It's as large as most full-size backpacks by eBags/Northface/etc. or at least pretty close. Going by the measurements listed here it's 1400 cubic inches. Compare that to other collapsible daypacks like Rick Steve's Civita which is less than 1000. This bag is at least 50 percent larger (if not 100 percent) than other collapsible daypacks, and that's the reason I got it. As a large man I don't want some purse-like wrinkly bag, but a normal backpack when unpacked. The straps on this are also sufficiently long, whereas other collapsible bags I can't even fit over my arms. The material is very nice, it looks like lightweight dark denim, and feels similar to denim although obviously it feels synthetic. It's pretty flimsy though, although the lower back and bottom are more rigid because they consist of the sides of the case it folds into. This means the bag stands up pretty readily. The interior is black with a silk-like sheen (and slippery, a good think for removing items). The front pocket is very small, it does not run the length of the front and would not fit a boarding pass for example, although it will fit a passport or wallet or cell phone. The straps are nice, with some padding towards the back where they go over your shoulders. Having seen and used several other collapsible daypacks (RS Civita, Sea to Summit Ultrasil) I have to say this is the only one that feels like a real backpack. That said it does not collapse as small, although it folds up into a rigid rectangular shape which is easy to pack. Overall I highly recommend it, Tumi did a great job of taking an idea (packable backpack) and turning it into something that I would actually want to use on a daily basis."