The cards would have been printed by Visual Panographics, which held the Xograph trademark (which is why it was seen on the cards), and was responsible for all Xograph printing. Visual Panographics in turn was a subsidiary of Cowles Communications, which published Look magazine. If you are unfamiliar with it, Look was a major competitor to Life magazine, back when magazines were still a major form of information and entertainment. Cowles Communications was the first company to successfully mass produce a 3-D photo, which appeared in the February 25, 1964 issue of Look and featured a bust of Thomas Edison. Eight million copies allegedly were sold:
Here's the skinny, right from the magazine:
You can see from the blurb that Look (Cowles Communications) owned the sole printing press able to manufacture lenticular pictures. This development would have caught the attention of Woody Gelman, I am sure. Topps first started to experiment with the technology around 1967 and diligently started work on the 3-D Baseball cards during this time. As we have seen previously, many of the proof cards from this set have Xograph/Visual Panographics stamps on the back:
The set famously had production issues and after playing around with the technology for a couple of years, Topps basically gave up on it. Kellogg's stepped into the breech of licensed 3-D sports cards of course but the technology as a whole was pretty much done with as a viable commercial venture by the end of the 70's, although Kellogg's and later Sportflics would soldier on with it into the 80's.
However, what is intriguing to me is that, while 3-D Baseball had no Topps markings at all on the (blank backed) cards, a 1969 3-D set called Go-Go Buttons did have Topps indicia:
I can only assume Topps used a competing technology to produce the set and would think it could have been from Vari-Vue, which was really known for fusing lenticular technology with buttons. Despite the "Japan" designation, Topps was not in the habit of using knockoffs so I have to believe the 3-D effect was properly licensed and Vari-Vue indeed issued licenses in that country. There was also a Japanese company called Toppan that manufactured and printed lenticular work in Japan (and elsewhere) and may actually have sold the technology to one of the US "3-D" firms following the expiration of a licensing deal. I'm not positive but it seems to me the photographic process, which used a single lens and required a very specialized and expensive camera, differed enough from the"stereoscopic" method, which used two lenses and interlaced the resulting images, that the latter was a lot cheaper to use in production.
Go-Go Buttons are quite groovy and their packaging was outtasight man:
The reverse had a handy checklist:
There is an excellent doctoral thesis on the various lenticular processes here, which really helped me see how the different technologies came about.