Birkenstock and Ader Error collaborate for the Boston clog's 50th anniversary

Birkenstock is marking the 50th anniversary of the Boston clog with a second collaboration with Seoul-based fashion brand Ader Error. The capsule reinterprets the closed-toe silhouette, first introduced in 1976, in two styles — the Boston Cap and Boston Flap — around a concept the partners call "Thread," using stitch detailing and Ader Error's zigzag embroidery. The Boston Cap comes in black and camel with a dual-layer leather upper and utilitarian leather cap; the Boston Flap, offered in Ader Error's Ultra Blue and a Honey tone, adds an exaggerated upper flap fixed with white whipstitch.

The release is the latest in a run of limited collaborations Birkenstock has used to keep core silhouettes in cultural circulation. In June, Sacai unveiled two new silhouettes created in collaboration with the German shoe company in Paris at its spring/summer 2027 show. Sacai created two new footwear models, Cassette 75 and Aoyama 107, which were inspired by three key styles from the brand, including the one-strap Madrid, the Arizona sandal and the Boston clog.

In July, Birkenstock announced a collaboration with heritage French footwear brand Repetto, as part of its Paris-based special projects line, Birkenstock 1774.

The Boston is among the brand's highest-volume styles. In fiscal 2025, Birkenstock's Americas segment grew 18 percent in constant currency, reflecting demand for its higher-priced Arizona sandals and Boston clogs, as the company sold more than 38 million pairs of footwear over the year, up more than 12 percent, with average selling prices rising 5 percent in constant currency.

The Birkenstock x Ader Error capsule also falls under Birkenstock 1774 and launches globally on Thursday through 1774.com. It is the two brands' second project together and their first in four years. Their debut collaboration arrived in May 2022 under the theme "Too Passionate to Stop," bringing Ader Error's creative direction to four Birkenstock models — the Gizeh, Arizona and Milano, plus the hard-wearing A630 PU clog — with detailing the brands linked to snow sports and the technical construction of ski boots.