Last week we purchased two large framed pictures, 24" X  22" that we thought  would fit in our suitcase.     Well they almost fit, but are a wee bit to big.     Does anyone know of a place in Pattaya that does packing/crating where we can get a box custom made for our pics?       We will check it in on the airline as checked baggage when we go to the USA in September.      I asked a couple of places that sell paintings  but none made boxes.

You could try one of the shops around town that makes wooden furniture to order. I'm sure they could make a sturdy plywood box to your specifications. If you don't know of any such shops then you can try Jar furniture shop, on Thepprasit directly across the road from Soi 10.