I'm looking for the 4x5 film that was sold preloaded by Kodak, so you could shoot about ten or twenty shots without having to carry 4x5 film holders. If the 4x5 size is no longer available, is 3-1/4 x 4-1/4 or another size still available? I'm looking for Tri-X or similar B+W film. If none of the above is still made, what are my options ?
Your options are loose sheets, Kodak Readyload, Fuji Quickload, and Polaroid Type 55 P/N. There are a few good articles on all the available filmholder systems on Paul Butzi's website (I think that's www.butzi.net, but if not, just google it).
Sadly film packs are no longer produced. In the past they were produced by Kodak and agfa, possibly others, inseveral emulsions. They held 16 sheets of roll film and were fast and easy to use.
I am down to my last 12 packs of Tri-X and will miss them when they are gone.
There are still small stocks of Fuji Quickchange cartridges, e.g. at Megaperls. They take 8 sheets and can be reloaded. You'd need a Quickchange cassette and one or more of these cartridges.
There's also Grafmatic holders, ebay is pretty flooded with them lately, though I'm worried that'll slow down by the time I have any money...
They hold 6 frames each and are about the same size as a normal 2 frame cut film holder. Not quite as many as these film packs (never heard of them before?) but still, 3 times as much as you'd have otherwise.