28

Twenty-eight centimetres is the Kelly's natural size. It is large enough to be genuinely useful and small enough to keep the proportions elegant, and it is where most people end up after considering the alternatives.

Capacity

A full wallet, phone, keys, cosmetics, sunglasses and a small notebook. Not a laptop. The Kelly's trapezoidal shape narrows towards the top and the flap steals depth, so a 28 holds less than a Birkin 30 despite the numbers looking close — worth understanding if you are cross-shopping the two.

The shoulder strap makes a real difference at this size. A 28 worn across the body is a comfortable, all-day proposition in a way that hand-carrying it is not.

Sellier or Retourne

This is the size where the construction question matters most, because both work.

Sellier in Epsom gives the crisp, architectural line and commands the higher premium. Retourne in Togo is softer, roomier and easier to live with. Neither is the better bag; they are different objects.

Inspecting a 28

The front straps and their tips take the most handling of anything on the bag. Check the stitching where each strap meets the body, and look at the plating on the turn-lock and the strap studs.

On Sellier examples, examine the exterior seams and the edge paint along them under direct light. On Retourne, look at the base corners, which soften rather than rub through and are easier to miss in flattering photography.

At resale

The 28 is the most liquid Kelly size, and a Sellier 28 in a neutral colour is among the most consistently sought configurations in the entire market. It has never been difficult to sell.