Since the cards aren't really worth much I decided to forgo putting them in top loaders. For damaged cards and the cheaper sets (1979+) I tend to just put them in 9-pocket sheets. That was my plan for the 1981s.
My problem with the 1981? Just like regular baseball cards, some of the 1981s don't fit well into pages since Kellogg's made them 2.5 by 3.5 inches just like standard cards. The thinner stock on the Kellogg's cards can make them difficult to slide into some of the pages. They cards aren't valuable enough to track and search which pages to use. I've been going with recycled pages that are from all different brands and years.
The cards in yellow on the right of each picture are the 1981s. See how they compare to other years.