|A 1920s Graflex film pack|
Kodak and Ansco supplied packs of ready to use 4x5 and other size sheet film in the late 30s, 40s and 50s for use with packfilm adapters on press cameras. Press photographers paid the extra price to have this pack of Tri-X ready to go. If you see a pack film adapter, you will notice that it looks like a 550 style holder for instant film packs.
Here is a link to details about the early pack films with a cross section view of how one is assembled.
Polaroid knew about packfilm and had ideas to produce pack film from almost the beginning of their photography business. But, packfilm was complicated, and required expensive machinery to produce. The choice of "picture rolls" also known as Polaroid roll film, was the result. Picture rolls were produced until the early 90s, when they were discontinued. 20x24 Studio still uses a big "picture roll" of sorts, with two rolls in the camera, one the negative, the other the positive.
After the business grew and improvements were needed, and the capital was available, the decision to switch over to packfilm was made. Both Polaroid and Fuji made packfilm. Fuji still makes some of the smaller pack film today, but has discontinued 4x5 pack film completely, due to poor sales. Poor sales of the pack film were blamed on the high cost, but that's not the entire story. Few 4x5 pack film backs were manufactured compared with the smaller backs that shared the same format with millions of still working pack film cameras. With so many "mouths to feed" Fuji enjoys sales to those cameras that take the smaller pack film. Those who still have a stock of 4x5 Fuji pack film are fortunate.
Polaroid also had 4x5 single sheet from very early on and produced it for about 50 years.
There really is no reason for us to make pack film, especially not in 4x5. The sales figures would not support it, and the value proposition to the user is not as good as its single sheet cousin that can produce a positive print and a high quality negative with one exposure. Even this improved value still needs to be proven in the marketplace and steps are being taken to learn if the market is strong enough to support that product. We think it might as there are more of the 545 type backs in the world than any of the pack film backs, and nearly all of the 545 backs are still in operating condition, a testament to their durability.