If Antwerp’s Mode Museum (MoMu) is desperately seeking a second storage space for its growing permanent collection, at least part of the blame falls on Bernard Willhelm. He may donate his designs each season alongside the likes of Dries van Noten, Martin Margiela, and his onetime mentor Walter van Beirendonck, but inside the museum’s existing archive rooms — which Sight Unseen had the exclusive privilege of touring earlier this year — it’s Willhelm who clearly holds the record for overflowing racks. In fact, MoMu’s curation team rarely turns down a donation from a legitimate source, whether for the historical collection it originally inherited from an old provincial textile museum or for its cache of contemporary fashions by talents born or educated in Antwerp, but Willhelm’s contributions are so generous that the day we visited, there were clothes waiting to be graciously returned to his showroom. It’s not difficult to understand the designer’s enthusiasm, though, or that of his peers: The MoMu’s prestige in Europe far exceeds its diminutive size, and since it opened a decade ago, it’s become the largest repository in the world for contemporary Belgian fashion.

Of course, of the 25,000 items in its possession — which multiply at a rate of about 500 new acquisitions per season, hence the need for additional storage—only a tiny fraction are on view at any given time. That’s the case for most museums, but MoMu only puts on two temporary exhibitions per year in its corner of Antwerp’s ModeNatie building, in addition to the few hundred items it keeps on permanent display. That’s why it was so appealing to us to approach the museum for a peek into the archives; museum curator and art historian Wim Mertens spent several hours leading us through the stacks and dragging out boxes full of Margiela accessories and antique lace samples, and yet we walked away feeling like we’d left behind a box of buried treasure. Luckily the museum has managed to document just over half of its collection in an online lookbook — check out the slideshow documenting our visit at right, then click here to dig into MoMu’s rich digital repository.