the library systems of danish designers like mogens koch achieve an almost weightless modular wooden cabinetry by making the walls as thin as possible. the cabinets lose very little by way of strength because they are made of solid wood and dovetail joined. this is consummate danish craftsmanship, still executed with exacting detail in the beautiful rud. rasmussen workshop in copenhagen. the boxes of the koch system can stack on top of and beside each other without looking bulky or clumsy because the total thickness of two sides placed together is still amazingly thin. of course, you get what you pay for, and when it comes to vintage danish masterpieces like these, you pay even more.
the ikea cases below (which already read a bit thinner than most of ikea's cases) go some way to answering the "thinness" problem by starting with one case, then providing add-ons with only one side. this prevents the doubling-up of sides that can make placing cases like the billy together into a heavy-looking affair. i don't mean to suggest they are anywhere near the league of the koch cases, but i do wish more cases had this option.