Count on packing pretty light.  Bring one medium bag to check in, and a carry-on that can double as an everyday bag to carry with you for the trip  A backpack or courier-type bag is appropriate for the carry-on.

Most international airlines allow two checked bags. However, for this trip, you are allowed ONLY ONE. It must fit this criteria:

• 3 dimensions of each bag may not exceed 62 in. (158 cm)
• Weight of each bag may not exceed 50 lb (23 Kg)

DO NOT OVERPACK.  One medium bag should be sufficient, along with a carry-on large enough to carry at least a days worth of clothing and gear.  If you need something, you can always get it cheap in Bangkok. We will be traveling by van from Bangkok to Buriram Province to Chiang Mai and back to Bangkok, and there isn’t a lot of cargo room.  If you have two large suitcases, your van mates will not be happy.

A lot of participants in previous trips did a fair amount of shopping.  This is another advantage of packing only one bag; you can fly back the bag previously filled with donations instead filled with souvenirs and gifts. If this is something you may do, you might want to pack a lightweight duffel bag into your first bag. These are relatively inexpensive, very light and small (the one below from REI packs up smaller than a water bottle), and can fit quite a bit.. You can also purchase a bag in Thailand to bring back with you. If you don’t plan on bringing back 50 lbs of stuff, you can split a bag with one of your trip mates.

You aren’t going to have to lug your luggage long distances, so you don’t need anything fancy.  I plan on packing everything I need in a Cotopaxi Allpa 42L travel pack (pictured above). Something wheeled is nice, for those long slogs through international airports, but isn’t totally necessary. Plus, wheels and a frame take up space that could otherwise be used. You do NOT need to get anything fancy! Use what you have, as long as it isn’t too big and bulky. You can use backpacks, duffle bags, roller bags, or any other type of luggage.

Some other notes on baggage:

• I know I sound like a broken record, but start getting in the habit of packing light on trips like this. You won’t miss the extra stuff, and it’s incredibly liberating to travel for weeks or even months with everything in a backpack that you can check in when you fly. Remember, you can always buy anything you need when you get to your destination.
• Plan on carrying valuables, a day’s worth of clothing, prescription drugs, passports, wallets, jewelry, cameras, phones, and anything that you absolutely cannot get along with for a day in your carry on.  Bags do get lost, and it’s pretty depressing to not have at least a change of clothing handy.  Most of these situations resolve themselves within 24-48 hours, luckily.  Also, most airlines will offer you some cash for the inconvenience.  This is from personal experience (during a trip in summer, 2005, Korean Air kept our bags in Seoul instead of putting it on the flight to Bangkok; it could have been worse, since it at least stayed in the same continent, and we got them within 48 hours). You can get toiletries in Bangkok, so don’t worry too much about that.
• Airlines are getting stricter about the size of carry-on luggage. Most airlines allow one carry-on piece that measures a total of 45″ (length + width + height), with a maximum of 22 lbs. But then they also allow 2 bags of personal items such as laptops, purses, etc. I’ve carried a carry on plus a laptop bag with no problems, but other times, they get picky, and will weigh your carry-on. If they determine it is oversized, they will check the luggage, and if it exceeds the checked bag limits, they will charge you. ALL STUDENTS ARE RESPONSIBLE FOR ANY BAGGAGE FEES INCURRED DUE TO OVERWEIGHT OR OVERSIZED BAGS!!
• Don’t lock checked bags with a lock not approved by TSA, unless you want the locks broken.  Make sure if you use a lock, it is a TSA approved one. Federal regulations.
• Count on using your carry-on as an everyday bag, one that can fit your water bottle, a sweater or shawl, camera, and a few other things you may need access to during the day. As I said before, a daypack or a courier bag (depending on what you prefer) work great. I also like to bring a small sling or fanny pack, because sometimes I don’t need even a daypack for the things I carry. Plus, I can grab the sling from my carry on and put it under the seat on the plane. That way, I have easy access to anything I may need handy during the flight without going in the overhead bins for my carry-on, stuff like my passport and pen, journal, earbuds, and anything else I need handy. This video does a nice job illustrating the utility of these bags.