I received a few days ago a copy of the Freestyle Spring 2009 catalog. On the back page of the catalog there is a large banner advertising Arista B&W 35mm films. Inside that banner there is a small American flag, followed by the words "Manufactured in the USA".
Is someone in the USA really manufacturing the Arista B&W 35mm film?
Freestyle has used just about every manufacturer of film for their Arista brand line at one point or another. Currently they use Foma (for Arista.EDU Ultra), Kodak (for Arista Premium) and Fuji (for Legacy Pro). Previous suppliers have included Ilford (for Arista Pro, IIRC), Agfa (for Arista II), and Forte (for Arista.EDU -- note the lack of "Ultra" for this line). Ferrania supplies (or supplied -- rumor has it this is now another defunct line) the Arista color film. There may have been other suppliers in the past, too; these are just the ones from the last half dozen years or so.
Kodak is (as far as we know) the only producer of B&W film in the USA.
Other threads on APUG opine that Kodak produces the film (100 and 400). Unofficial tests infer that Plus-x and Tri x are being sold as Arista Premium. Legacy Pro is produced by Fuji Film.
In either case 120 roll film is not available. Only 35mm.
I (among others) can only hope that 120 will follow.
Does anyone have an educated guess as to how Plus-X (or something like it) came to change its nominal ASA from 125 to 100? It seems like it must represent either a slight variation of the production (but why?), or a "close enough" fudging of the speed (which seems uncharacteristically sloppy for Freestyle).
I think it's the latter. In any case, that 1/3 stop doesn't add up to very much and doesn't hurt anything if you overexpose by that much. That small difference is swamped by other factors. The only manufacturer of B&W films in the US is Kodak. Both the Arista Premium films, the 100 and 400, look, smell, and feel like Plus-X and Tri-X. They most certainly are not TMax 100 and 400.
In case you do not know it the International Organization for Standardization (ISO) said over a decade ago that films do not have a set ISO speed. The film speed will can be higher or lower depending on the developer and developing conditions. So there really is no difference between 100 and 125 speed film unless the developer and conditions (dilution, inversion rate etc.) used to determine the ISO speed are given.