Gregory optic 48 best ultralight waterproof backpack: At $300 (£222, au$407), the nomatic travel backpack is not exactly a bargain, but given its versatility, the quality of materials and thoughtful. It’s neither bulky nor unwieldy, so you can move more easily through airport security or the aisles of airplanes and trains. Lululemon has four backpacks in its city adventurer line, and this 17l size is a recent addition. And is perfectly sized at 12 x 5.78 x 18.50 inches for travel.