I've been using these plastic storage containers to store filament for a while now, and they work very well for most of my spools. There are a couple larger spools (also 1kg) which are an uncommon wider design that do not fit these as well (they still work but are tight), but the vast majority of my spools do fit easily. I've seen these below $20 for a six pack prevously, but they are currently pretty close to that at $21.29 after a $3 coupon. They're hard to beat at only about $3.50 each. They also come with a bunch of the black labels, a white pen which has an ink that washes off with water, as well as a measuring cup and some other parts which are not needed for what I use them for. The only downside is not knowing what to do with all the extra measuring cups :D
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