Airbac backpacks have an inflatable rubber bladder built into the lumbar/gluteal region of the pack, providing cushioning, easing stress, and distributing content weight more evenly. Air is added or removed via a little pinhole mechanism in the bladder (a hand-pump is not included, but the cushion comes pre-inflated and stays that way about a year). While the company makes heavy duty packs for hikers and photographers, I especially like the lightweight little Mesh Backpack model, which measures 12.5 inches across by 6 inches deep, by 19 inches high. The pack’s padded nylon back and adjustable back straps and inflatable lumbar cushion provide plenty of structural support. But the roomy zippered main compartment, external zippered pouch, and two side pockets are made of featherweight nylon mesh, so they are quick-drying, and you can see the contents — a boon in my book. (Use any opaque plastic bag to shield items from visibility). My only quibble is that the air bladder is not removable, which makes the pack bulkier and more space-consuming than I might want for lightweight loads. Comes in neon colors, black or grey.
Airbac Mesh Backpack is $49.99 at www.airbac.com.