Packable bag

I take one every trip, usually a basic lightweight duffel. I currently have a North Face Flyweight, but have used others including even a cheap foldable one off the rack at Target. Whichever one is handy while packing. You can even buy one over there, from those cheap luggage or sport shops if necessary.

How sturdy ? IKEA has little foldup nylon bags under $10 which zip closed -- good for soft clothes. Weight in ounces. Probably best to check your regular bag, use this one for carry-on or "personal item"

I used the RS Hideaway Tote, often called the "don't tell Rick bag" last May. It's very light, packs fairly small into its own pocket, and is on sale right now. I packed it with dirty clothes and such as a carry-on, so I could expand my RS rolling bag to check with a couple of bottles of olive oil coming home from Italy.

Although a rather pricey light-but-sturdy option may exist, the choices I've encountered during casual shopping trips have all fallen into one of two categories:

• cheap/lightweight/compact/not sturdy
• expensive/heavier/bulkier/sturdy

I have both types and have to make a choice before each trip. The very lightweight, cheap bags (which one used to be able to buy for about $1, but they're probably more like $6-$10 now) tend to rip at the seams if you carry heavy purchases in them for very long. Not ideal if you plan to use the bag for grocery shopping or are inclined to buy things like books or ceramics.

Another vote for the RS tote. They're large and sturdy and pack small. Great for laundry, beach, etc. We take one on every trip.

I checked an RS tote from Paris to Denver - 2 Eagle Creek med. packing folders of dirty clothes with soft items sandwiched in the middle. Wasn't sure the bag would withstand checking for international flight & connections, but it did fine. That free up my roller carryon for books, scarves, tablecloth from Provence, etc.

We always travel with a compressed flat bag that can be used as either a carry on bag OR the carry on bag if we check something else.

We hate to buy souvenirs, but hey - cool things happen when you travel.

If you carry an extra bag, don't forget to carry a spare luggage tag and a spare lock. In fact, we always travel with a spare lock in case one goes missing in transit.

I have the "don't tell Rick" bag, I usually tuck it into a shoe for packing, have used it several times.

I generally use my daybag (the Civita is easy to pack) for laundry, shopping - it holds a lot. Items you want to use on laundry day (phone, book or tablet, wallet, water bottle) can go in the zipper or mesh compartments.

Does it need to zip at the top? If you will be checking it or shoving it in bus storage then a zip top is important. I don’t use it for that - I will put overflow items in it for my underseat bag or carry it over my shoulder with purchases/groceries when out and about. So no zipper.

I have the rume medium shopping tote - it folds up tiny and is very, very light so I can shove it in a corner of my purse and use it if I need it anytime. On the plane home I will have my purse plus a few overflow items in it as my underseat bag. I can check my carry on suitcase after filling it up beyond carryon limits if needed.

For the purposes of stowing extra stuff so I can check a bag, I use an old large promotional bag (the kind they give away at conferences) that has a zipper. I used the same bag to corral stuff in our hotels - which were usually dimly lit and hard to find misplaced items in. You should be able to find something like that in any thrift store.

On a slightly different note, since people mentioned daypacks...
On our last trip (Village Italy 2017) backpacks were not allowed in many places - bags of the same size were often fine (go figure). Our (RS) guide explained that it's a new "security thing." For the purposes of getting around I used a foldable backpack (pick a well-rated one on Amazon) + a homemade travel vest with massive storage space. If my backpack was not allowed, I stuffed everything into my vest and folded the backpack. I've seen (expensive) backpacks that convert to bags in specialty stores. If you can find a reasonably priced item like that, it might be a good purchase. Or bring a small foldable bag inside your foldable backpack (gr).

I just purchase a zipper top bag when I am there and get great use out of them all year long. I have one from Paris, Rome, Florence, Cinque Terre, Sorrento....love them all.

I always prefer the Sea to Summit line for durable packable bags.

I usually bring the sling bag tote (2.2 oz) when I'm traveling with only an underseat bag.

Another bag that is excellent is their ultra light duffel (2.8 oz).

Both bags compress into keychain size bags. If I have to check bags I check the carry on. I take the packable bag into the cabin.

Please note that some users think that the ultra sil fabric is fragile because it is so light. Ultra sil is actually quite strong. The users are equating heavy wih bomb proof, which isn't correct. Abrasion and tear resistance is a combination of factors. Some lighter materials are actually stronger than heavier ones.

This falls into the expensive/lightweight/compact/sturdy category

Wow -- thanks for the help, lots of great options!

Thanks for this post OP... I just got back from a 4 week trip and didn't bring an extra bag... boy did I wish I had. I actually have one and it goes on my "to pack" sheet today!

I pack one of these when we go to Europe or beach destinations, such as Hawaii: Amazon Item: "FLIP AND TUMBLE – Premium Reusable Grocery Bag - perfect Shopping Bag, Beach Bag, Travel Bag, Green". I've used it for the misc. stuff I want at my feet on the plane, for groceries, and for the beach. The bag folds into itself into a tiny ball, but is sturdy enough for a couple of beach towels & misc.

My husband & I both take a roller carry-on, and we pack an empty smaller backpack in one of our bags. We use the backpack if we're hiking. Usually by the end of the trip, one of us has the backpack as a personal item on the plane ride home.

REI makes a line called "roadtripper duffel." We have the small, https://www.rei.com/product/870769/rei-co-op-roadtripper-duffel-small and have used it many times. It folds to just larger than a frisbee and has a removable long shoulder strap should you want to check it. I like it because it's more heavy duty than a nylon bag. It's perfect as the "extra" bag we all seem to need on the way home.
Ikea has several lightweight bags without zippers that fold into a small pocket. They don't have a zipper, but are perfect to carry dirty clothes to the laundry, put a sweater in when it's a bit warm, and carry a heavy purchase.

Yes, Le Sportsac weekender. It weighs next to nothing and folds easily to take up very little room. It is very durable as I've had mine for over 25 years. It's more than paid for itself.

I have one of these to use for groceries or carrying my coat during the day. I also have this one for bringing things home (not as checked luggage - use on plane). The first one is super tiny; the second is bulkier but lays flat in the bottom of my backpack. Both purchased at the Container Store.

I like to use Outlander backpack. Their bags are very light. If you are looking for more option then find here top rated small edc backpack 2017 list.

In addition to the above options, check out eagle creek packable totes. There's also packable backpacks. Eagle Creek makes good products. The RS tote is a good option for a simple, packable tote.
A simple cinch sack (available in camping section at Walmart) is a cheap workable option.

I was going to add my bag, but I see you have tons of good suggestions.

Just so you know, we always travel with a bag that folds flat so just in case we need to check something extra on the way home, we can check the bag with the dirty laundry and have a bag that fits the dimensions of carryons for most airlines.

Have a great trip!!