Hermès HAC à Dos PM vs GM: Complete Backpack Size Guide

The HAC à Dos: Hermès’s Most Distinctive Backpack

The Hermès HAC à Dos is unlike anything else in the Hermès catalogue. It takes the Haut à Courroies — the house’s oldest bag design, originally built to carry saddles and riding equipment — and reinterprets it as a structured backpack for modern daily use. À Dos is French for on the back, and that is exactly what it does: the HAC’s characteristic exterior straps, which on the classic HAC cross the front of the bag, become the shoulder carry system on the À Dos version.

It comes in two sizes: the PM (petit modèle) and the GM (grand modèle). Choosing between them is the central question most buyers face, and the answer depends almost entirely on what you need the bag to do.

The HAC à Dos PM: Everyday Carry in HAC Form

The HAC à Dos PM is the smaller of the two sizes. It carries roughly what a well-edited daily bag should: a wallet, phone, keys, a small notebook, earbuds, and light essentials. It does not hold a full-size laptop, and it is not meant to — the PM is designed as a refined everyday carry piece rather than a work or travel bag.

What sets it apart from other luxury backpacks is the HAC’s signature structure. The PM holds its shape when worn empty, sitting upright on your back rather than slumping against it. The exterior strap detailing reads immediately as HAC to anyone familiar with the line, which gives it a level of distinction that even a Birkin does not always achieve in the same room.

The PM is more commonly seen on the secondary market than the GM, which makes it the more accessible entry point into the HAC À Dos line. It is most often found in Togo and Clémence in classic colourways — black and étoupe dominate, with gold and raisin appearing occasionally.

The HAC à Dos GM: Travel and Weekend Scale

The HAC à Dos GM is the larger version, and it operates in a different category entirely. Where the PM is a daily carry bag, the GM is closer to a luxury weekend or travel backpack. Its capacity approaches that of the HAC 50 in carry volume, and it functions well as an alternative to a traditional carry-on for buyers who want hands-free travel without sacrificing the HAC’s equestrian identity.

The GM is rarer than the PM on the secondary market, which makes finding a specific leather and colour combination genuinely difficult. That scarcity is part of its appeal for collectors who specifically want the large-format HAC À Dos, but it does mean patience is usually required.

Hardware on the GM is typically palladium, which suits its more contemporary styling better than gold. The structured body holds its shape at the larger scale just as reliably as the PM, which is no small feat — most backpacks at this size slouch considerably when not fully packed.

PM vs GM: A Direct Comparison

What Makes the HAC à Dos Different from Other Luxury Backpacks

Most luxury backpacks are soft-sided bags with a brand logo applied to them. The Hermès HAC à Dos is a structured object — it has the same architectural quality as the classic HAC, just reconfigured for back carry. The exterior strap system that functions as the shoulder carry is the same strap design that has defined the HAC line since the 1890s. That continuity of design is part of what makes the À Dos compelling to buyers who care about the history of the house rather than just the label.

It is also considerably rarer than the Birkin or Kelly in either size, which means it reads as a more considered choice to people in the know — the kind of bag that signals deep familiarity with the Hermès catalogue rather than a straightforward status purchase.

Leathers and Care

Both the PM and GM are most commonly produced in Togo and Clémence, both of which are well suited to backpack use. They handle the daily friction of being set down, picked up, and worn against clothing better than smoother leathers like Box Calf or Swift. Togo in particular is highly scratch-resistant and maintains its appearance well under regular use.

Care is the same as for any Hermès leather: store upright with the original stuffing to maintain the structure, keep out of direct sunlight, and clean with a soft, slightly damp cloth. Avoid leather conditioners not specifically designed for the leather type — when in doubt, take it to a professional leather specialist rather than treating it at home.

Browse the HAC à Dos Collection

Explore our HAC à Dos PM and HAC à Dos GM listings, or return to the complete Hermès HAC and Birkin size guide to compare all available sizes.