Wire lattices form the backs of this pair of chairs by Rotterdam-based Studio WM for Danish brand Menu, with one positioned the opposite way around to the other.

Design Academy Eindhoven graduates Wendy Legro and Maarten Collignon of Studio WM each designed one of the two wire chairs before realising they'd sketched the same back design but positioned it a different way up.

The two WM String chairs are both made from a powder-coated steel tubing frame, with a wire seat and an oversized wire back.

The lounge chair features a lower seat than the dining chair, with the wider edge of the trapezium-shaped wire back at the top rather than the bottom.

The forms of the chairs were designed so they would still look interesting when pushed under a table. The shapes of the chair backs also reflect the intended sitting position of the user.

"The backs reflect the mood or energy that is created by the sitting position they trigger," Legro told Dezeen. "For the dining chair this is quite active, whereas the lounge chair is more lazy and relaxed."

Although the matching inverted shapes of the two chair backs seem to have been designed in tandem, Collignon sketched the dining chair and Legro drew an outline for the lounge chair separately.

It was only when the two compared notes that they noticed the similarity and decided to pair up the designs.

Metal wire was chosen for the main material to create a "thin and elegant" chair that was still functional.

"The strength of metal gave us the freedom to push the boundaries and seek the thinnest, most light construction to bring light into the design in a literal and figurative sense," said Collignon. "The contrast between the thin metal wire and soft pillow evokes the urge to touch and use the product."

The String design is available as the WM dining chair and the low WM Lounge Chair, in black or white. Both come with cushions upholstered in fabric by Danish brand Kvadrat.