The plastic tabs on the CD insert scraped against the cube walls. I shoved it in, heard that cheap crack, and realized I'd bought the insert for the 13-inch cube, not the 13 1/8-inch one. That eighth of an inch matters. I learned it the hard way so you don't have to.
Kallax CD storage is simple enough. You have a cube, you slip in a wooden or plastic insert that holds CDs. But there are two sizes of Kallax cubes — the 13-inch and the 13 1/8-inch — and the inserts aren't interchangeable. The bigger ones are for the older 'Expedit' line. They're close enough to look right, but they don't click in. They sit loose. They rattle. If you have shelves full of CDs, that gets old fast.
The Insert I Should Have Bought
The one that fits the newer Kallax is the 33x33x33 cm insert. That's the one with the little tabs that lock into the corners. It holds about 60 CDs per cube. I have two of them now, and they don't move. You can grab a CD without the whole stack sliding.
What I Actually Did Wrong
I bought a used lot from someone who said they were from an old Expedit. They looked fine in the photos. But when I tried to fit them, they were a hair too big. I forced one in, scratched the finish, and it still sat crooked. I ended up returning them and ordering the right ones. Cost me a week of waiting and my time.
Measuring the Insert
Before you click buy, measure the inside of your Kallax cube. It should be around 33 cm or 13 inches. If it's a hair over, you're fine. But don't just look at the outer frame. The insert has to fit the opening. And check the product description — if it says 'fits Expedit' but not 'Kallax,' be careful. Expedit cubes are a tiny bit bigger.
Which CDs Actually Work
Standard jewel cases fit fine. Slim double cases fit. Digipaks are a pain because the spines don't line up, but they fit. If you have a lot of thick box sets, skip the insert — they won't fit a cube. For regular CDs, the insert is the way to go. It also keeps the dust off.
If you're rearranging your living room and planning around storage, take a look at More guides in Storage & Organization for other ideas. And if you're thinking about other cube-based storage, the TV Stand with Storage Cubes: What I Learned After Buying Three might help.
Measure first. Then buy. That's it.