The Kelly Sellier is celebrated for its sharp, structured edges and polished lines, creating a sleek and formal look. In contrast, the Kelly Retourne features softer edges and a relaxed shape, giving it a more relaxes vibe. 

The difference in craftsmanship is related to the unique structure of each style. The Hermes Kelly Sellier is crafted with external stitching, resulting in a rigid, boxy frame. This structured shape is further enhanced by the use of firmer leathers like Epsom, Box, and exotic skins such as Crocodile and Alligator, which naturally hold their shape and add to its polished appearance.

The Hermes Kelly Retourne is stitched internally, resulting in a softer, relaxed silhouette. The use of supple leathers like Togo and Clemence contributes to its casual, slouchy look while maintaining the luxury and durability Hermès is known for.

The Kelly Bag was originally crafted in the Sellier silhouette, and to this day, the clean lines are far more popular. 

While most Hermes Kelly Bags are available in both silhouettes, the Mini Kelly is produced exclusively in the Sellier silhouette. The Mini Kelly is less commonly produced, adding to its exclusivity and desirability. This rarity, combined with its structured design, has made it a must-have for collectors.

Whether you prefer the sharp elegance of the Kelly Sellier or the relaxed sophistication of the Kelly Retourne, both styles represent the pinnacle of Hermès craftsmanship and design.