In the 60's, the toy company Kenner released a cheap version of a Viewmaster, called a SEE-A-SHOW. Unlike a Viewmaster, which had a rotating disk with film images embedded in it, the SEE-A-SHOW merely had a thin card you pulled down through the viewer. One is seen here at the left. The images appeared in 3-D, but you needed a fairly strong light source to view it. It's read from bottom to top.
I thought it would be fun to share the ones I recently found in my basement! For your reading convenience, I've assembled the strips into a more traditional configuration. Click to enlarge...
Spider-Man falling down the pit is the most impressive 3-D effect in the bunch.
For its sheer goofiness, this Hulk one might be my favorite.
Super-hero stories don't get much more straight forward than this Thor one!
The Fantastic Four rated a two-parter!