The Outer Limits trading card set was released by Topps (under their 'Bubbles Inc.' pseudonym, which had also been used for the Mars Attacks set) in 1964. There were 50 cards and no stickers.
Card fronts depicted a (hand-tinted?) photo still from an episode of the Outer Limits TV series, surrounded by an uneven black border, with the card title in yellow beneath.
Card backs were in black, with a yellow meteorite silhouette giving the card number, streaking across the top; below this was the card title in whie. Dominating the center was a large yellow block of text, giving a story about the photo from the card front, with a stylized Outer Limits logo and 'Collect All 50 Cards' at the bottom.
This is a favorite set among many collectors for its imaginative design and fantastic photos of some of the more grotesque monsters to appear on the TV series (which seemed to feature a different gruesome character of sort sort in every episode).
The funny thing is, the text stories on the card backs have almost nothing to do with the episodes from which the photos were taken. Either the Topps company were given the photos without any information accompanying them, or they decided to ignore the onscreen stories and make up their own.