Once we had the bags in hand, we checked each model for what it could carry and the intuitiveness of the interior organization. To do so, we assembled a standard kit with a week’s worth of sundries: shampoo, body wash, lotion, face wash, toothbrush, floss, toothpaste, deodorant, and razor. We used both store-bought and hotel-hoarded versions, as well as the differently shaped pieces within our top pick for toiletry bottles (we used the entire contents of the Nalgene Travel Kit). We fit them several ways within each bag.
We then added more items until the bag would no longer close. Our first addition to all of the aforementioned essentials included conditioner, sunscreen, hair spray, facial tissue, and an all-purpose balm. The second addition (if all of the above fit) included some makeup: eyeliner, concealer, under-eye cream, mascara, blush, makeup brushes, lip gloss, makeup sponges, and cotton swabs. For the largest bags that could still fit more, we threw in all of the above plus a travel-size flat iron or electric razor.
Along the way, we noted the shape of each full bag, the ease of closing it for transport, and how readily we could access items when it was hanging and full. We also shook the bags when they were full and partially full—simulating transport—to make sure items stayed in place within the bag itself.
After checking the bags’ storage capacities, we tested their ability to contain a leak. We took one 3.4-ounce bottle filled with hand soap and dumped it into an interior pouch (if a bag had “leakproof” or plastic-lined compartments, as opposed to mesh-enclosed ones, that’s where the soap went). Then we shook the bags and watched for leaks or any obvious sign of moisture on the outside. Afterward we hand-washed the bags, dried them thoroughly, and then completed the same test with 3.4 ounces of water, representative of less viscous toiletries (such as eye-makeup remover or toner), for comparison.
We also took into account the weight of the bag, the style and size of the hanging hook (if present), any bonus features (removable shower caddy, mirrors, leakproof pouches), the standard price, and the breadth of the color choices available.