For my work I find myself living in many places (4 continents in the last 5 years). Some of these have limited / no access to postal services or even web access. As a result getting film can sometimes be hard. I need to rely on either asking someone to bring it for me, or I buy some when I am passing through a larger town.
So I need input from people for what B&W film is most easily found throughout the world. It would need to be easily bought by someone who is not a photographer. I would be looking for:
1) A film of around 100/21 ISO
2) A film of around 400/27 ISO
This is all so I can standardise on a film I can get consistently.
Ilford films and Foma films are pretty widely available,you could try Fomapan 100 and 400, or Ilford FP4+ AT 125 AND hp5+ AT 400. orn their delta 100 and 400
I don't have the limitations you do, but I'm still using Kodak products since I have some still. Still shooting Plus-X in 35mm and 120 as well as Tri-X.
In addition, and planning for the future, though, I'm shooting Ilford FP-4+ and HP-5+ since they appear to be the emulsions that will exist. It seems to me that the Ilford approach is about the only real way to standardize for the future and have any hopes of success in that goal.
Having been in situations where I've needed to buy film while travelling only Ilford B&W films are available consistently and mainly FP4 and HP5. Foma films are common as well but Kodak films are much harder to find.
I'm surprised no one has mentioned Fuji -- although I may be biased since I live in Japan, but I don't seem to recall ever having a problem finding it when needed.
As someone who also moves around a lot (3 continents in five years, but 6 moves in total), I feel your pain, although luckily enough I've always lived in places with a good postal system so I've relied heavily on getting stuff shipped from abroad most of the time. In all honesty I would focus on the films that you prefer to use, and equivalent back-ups if you can't find them exactly. In my case that would be Ilford HP5+/Kodak Tri-X, and Fuji Acros/Ilford Delta Pro. And like the others have mentioned, bring as much with you as you can when you go and keep it in the freezer or fridge until you can use it.
I use fuji across in 4x5 and 120 format, but don't know what the future gives. more and more are discontinued by fuji.
The 400 is also discontinued in 120 format, so i use kodak now instead. What's next...
Everywhere I have been (AU, US, EU, Russia, China) into a film shop, there has been HP5, FP4, TMY2 and often much much more. While I like Acros, it's often less available than Fujichrome. And despite comments above, I've never seen Fomapan on shelves outside of the EU and US.
Seconding the "buy a year's worth" suggestion, then you know what you have for sure. You'll probably pay half as much for it from B&H compared to most local shops.
Thank you to all who have taken the time to reply. The comments all seem to point to Ilford. This agrees with my observation, but it is good to get a better world wide sense.
I have never seen Foma at a shop, and it is a long time since I have seen Fuji b&w at a shop. Kodak unfortunately seems to be less common at the camera stores.
Agreed with the idea of buying a big batch of film, but storage can be an issue when there is no refrigeration, and there is a limit to how much film you can bring as carry on.
No/limited postal services? I'm just dying to know where you are going.
It sounds like a tautology, and it is: the most available film is the film that is available. If you can't order it, and have to take what the local store has on offer, then you are limited to what the store stocks.
The most common film is 35mm color negative, if you are in the middle of nowhere it is probably all you will find, and you may find yourself cracking open a disposable camera to get at it. There is nothing to prevent you from having a service bureau scan the color negatives you want to print and make high resolution large format B&W negatives from the scans.
Cleveland, Ohio has plenty of web and postal service, but to find B&W film you have to go to the few photography stores that are still in existence - a rather small number, I'm afraid, but they carry Kodak and a limited range of Ilford with Fuji only available in color.
Any of the standard B&W films will work well. The best technical performers are Kodak's Tmax-100 and Tmax-400. I buy them by the brick and keep them in the freezer. They keep for 10 years past expiration with no problems.