Here is what I took with me to Asia to paint with. I have an 11 x 14 OpenBox M panel holder. This is the core piece of equipment and I highly recommend this product. I have had this box for 7 or 8 years and it still works great. I had it refurbished by them before I left and I am sure it will last another few years.
I decided to take along Winsor and Newton Artisan water-soluble oil paints instead of regular oils. I did this because the last time I made a backpacker trip it seemed always to be a problem to get decent paint thinner. First of if you are in a foreign language country you have to figure out how to ask for it. And while I usually came up with a solvent that would work it seemed to be usually some toxic smelling substance that would end up leaking and smelling up all my luggage. Once in Mexico I ended up with whatever the locals sniffed to get high, and that also dissolved plastic. So the water based oils are definitely a better choice.
That said it took me a few weeks to get used to them. You really have to avoid water except for clean up. And you have to use one of the water based mediums to go along with it. Then they seem to perform closely to regular oils. I took along Winsor and Newton Artisan alkyd water oil medium as well as their water compatible linseed oil.
One issue with the water oils is that they take a long time to dry. Perhaps it is this climate: it is humid here. I was adding the alkyd medium at first but that seemed to dry to fast and come up a little when I painted over it during an alla prima session. So the answer here seems to be mixing in about 25 to 30 % alkyd medium with the linseed oil.
The pigment strength of the paints are also a little less than the Utrecht paints I am used to. They work OK, but I might opt for the Holbein water based paints the next time. They were much more expensive but they probably have more pigment and they claimed to have a faster drying time than regular water based oils.
I am painting on acid free mat-board primed with 2 coats of shellac. I brought along 9 x 12 in. panels and what I usually do is cut them up to size. I generally paint small while traveling. My storage box is a single 9 x 12 panel holder and I can attach several small paintings with clips.
In retrospect I wish I had brought along another 3 panel holder box as the paintings are taking longer to dry than I thought they would in this heat. I damaged a few paintings because they stuck together. Later in Thailand I got some loose plastic 3 ring binder inserts, which don’t stick to the paintings when I insert them in. Here even after a few weeks the surface of the painting feels gummy and soft. This may be because I used to much medium or the general high humidity here. I have also had some problems with the unused shellacked boards sticking. So everything works, but there are definitely extra considerations in a tropical climate.
I also spilled about half my alkyd medium and who knows where I can get that closer than Australia. Next time I will pre-mix my mixtures in little plastic bottles so that if one spills it is not a disaster. I also ended up with a Cad. Yellow light that was a little dried out. Again next time I will carefully check all the tubes. Check and recheck!
In addition, I brought along a brown paper sketchbook and a 10 ft. long 20 inch roll of Utrecht oil primed linen in case I have a chance to do some bigger work. All in all, it is a lot of stuff to lug around, but it is worth it once I am set up. I also discovered it is really is nice to have a scooter to ferry oneself around when you paint, so I rent one when I can.
“Nona” suggested painting on acrylic gesso primed surfaces because those surfaces would be more absorbent and speed drying.
My friend Scott Powers said while painting in China with regular oil paints he sometimes just used straight paint without thinner and then cleaned brushes later (sometimes even resorting to gasoline).