Little slits were made on pages of black paper to hold the cards in the pre-plastic days. However, Topps did themselves one better when they came up with an album for the Pixie gum card set known as X-Ray Roundup. Thanks to a pickup of three Pixie albums over the summer by Friend o'the Archive Tom Boblitt, we can take a look-see at a very clever construct.
The cover mimics that of the Hocus Focus album:
The trick here is captured in the cover text "with both sides always on show". Recall that the cards were designed with a magic "X-Ray" feature on the reverse. Well this album was designed to showcase both sides of the card while still using black paper pages:
Neat, huh?! Plastic pages have been around the hobby for almost 40 years now but before the late 70's it was paper all the way.
You can see the checklist peeking through. Topps subdivided the set into four broad subjects and moved the numbering around a little; here's some detail from the back inside cover:
That little viewer was a red plastic magnifying glass. I used to have one but it's been misplaced over the years. The packs included a red piece of cello to allow the hidden picture to show through:
The little peepholes allowed a partial glimpse of the x-ray!
The back of the album is blank, the tape is a later addition I guess, maybe the original owners attempt to house the cello paper?
The staples were possible as the album only had nine pages (and only held 81 cards). The earlier Hocus Focus album used brass fasteners.
The album ("holder") and "viewer" were advertised as part of the issue, this is the interior of the penny wrapper:
Considering vending boxes only had about 30 different subjects in a difficult collation and there were no nickel packs, I doubt more than a handful of folks put together a full set as a kid. Kudos to anyone who did!