I found this:
https://photo-3d.groups.io/g/main/topic/34845655
I don't know how current the information is, the web page is from c. 2000 (gee, that used to be a recent year...).
Well, let's see. Vectograph film is no more. After Polaroid sold their polarizer division to 3M, the film was promptly dropped.
Kodak stopped making matrix film long ago, so the only alternative was following a formula for making your own. The man who largely worked out the process is an accomplished dye transfer printer. Jim Browning is his name. Not for the faint of heart, his formula is complex and time consuming, but produces very good film.
StereoJet is essentially no more. Too bad because it eliminated the need for lots of darkroom work.
A stereo pair required perhaps 3-4 or more masks per view to control things like contrast. Then there were the required separation negatives and matrices. Spot on registration was required or your image fails. A manual darkroom process requiring perhaps more than 18 sheets of film, accurate registration and a print material with 3 layers--2 of them properly oriented and stretched PVA, is not going to interest too many people.
StereoJet eliminated the problem because it was largely a digital process. They used inkjet printing (and Photoshop) to greatly simplify the process. The images can be made using a more or less standard inkjet printers. No matrices and no darkroom needed.
One issue: the inks would not imbibe so they had Vectograph sheet coated with a layer that would accept the special inks.
The process I am interested in is black and white and printed with matrices. Joseph Mahler (yup, that Mahler family) developed the Vectograph Process around 1938 or so and Dr. Edwin Land hired him. They perfected the process but decided color was too hard and too expensive. I learned much from Vivian Wallworth who helped get StereoJet started. She worked with Dr. Land to perfect the Vectograph process and she helped me obtain materials.
Eventually, StereoJet started using undyed polarizer shock. They printed the color stereo pair on separate sheets and cemented the sheets together.
This is why I rattle on so about sharpness. What often goes unnoticed in a standard printed image does not go unnoticed in a stereoscopic view. Back in the day, you can see the increased grain when going from Kodachrome 25 to 64; not to mention, going from Kodachrome to Ektachrome.
But ... time change, tools and materials get better and I am perhaps too bloody old.
Bob