My most useful travel companion, the 4Monster Hiking Daypack, Water Resistant Lightweight Packable Backpack for Travel Camping Outdoor from Amazon. $18 to $27. Weight, a few ounces. https://www.amazon.com/4Monster-Resistant-Lightweight-Packable-Backpack/dp/B09NQSHK8Y/ref=sr_1_1?crid=H4VG8W7G7MQJ&dib=eyJ2IjoiMSJ9.dCb_bcOo9pOQP6rpLM4tDYT1AbCreIQLMse6rTG6-yTGjHj071QN20LucGBJIEps.tUawBatzbiE8mp6iuC4Cq3WJ5tEZ3mQpiQJNZ95lccY&dib_tag=se&keywords=4monster%2B30d&qid=1726998026&sprefix=4monster%2B30d%2Caps%2C364&sr=8-1&th=1
Comes in three sizes 16, 24 and 32L and a dozen colors. I’ve got the 32L because I purchased it for grocery shopping. If it were only for travel I think the 24L would be sufficient. I expected it to last a few months, you know how cheaply this stuff can be made. Going on 2 years now and not a single defect or frayed thread. To the astonishment of the store clerk it is strong enough to carry 6 liters of beer.
Shopping bags in Europe cost $$. Mostly it is tourist having to buy them because the locals generally travel with something reusable. That’s the reason I use this thing almost every day. I got a carabiner clip and I clip it to a belt loop and head out. If I find myself needing to buy something, I have it. Great at home and when on a trip. Hot day? The jacket goes in the backpack. Unexpected shopping stop, covered. Really big shopping trips I carry the giant OBI bag in it when I go out. No reason you couldn’t check it (full of dirty clothes maybe) if you needed to. I think it would survive the baggage handlers.
It has two pockets on the outside that Europeans would use for water bottles, Americans for personal hydration devices.
The only warnng is that this thing is completely unstructured, so its not for long hikes through the wilderness with heavy loads. But for a one or two hour jaunt filled to capacity with anything tha fits, its fine.