A radical formulation, Gerrit Thomas Rietveld’s Zig Zag chair pushed the boundaries of furniture design when it debuted in 1934. Rietveld spent years working to create a chair that mimicked the way humans sit, and the Zig Zag isn’t just comfortable and stable, it’s also stackable.

A member of the Dutch De Stijl (“The Style”) movement, Rietveld’s furniture designs reduced items to their most essential forms. That’s how a chair lost its legs and ended up in a Z formation. Originally, Rietveld hoped to make a chair that could be cut from a singular piece of material or “pop out of a machine, just like that.” He envisioned a bent steel plate, but joining together four pieces of plywood proved most effective and still amounted in the striking diagonal design.

Though it cuts a clean line, the construction (and addition of dovetail joints) belies its minimalist form. Rietveld’s vision wasn’t fully realized until Verner Panton designed his famous 1960 chair, but the Zig Zag marks an important moment in the collective process of reimagining the chair.