In 1956, Grace Kelly, by then Princess of Monaco, was photographed holding a Hermès handbag in front of her to shield her first pregnancy from the paparazzi. That photograph ran in Life magazine, and customers started pushing through the doors of Hermès boutiques to ask for the small ladies bag with straps. It had been around since the 1930s. It took a very public bit of hiding to make people want it.

I think about that when I look at the Hermès Mini Kelly. The story is about a bag that was practical first: saddle stitching, a trapezoid body, a small padlock, made almost entirely by one craftsman in about 18 to 20 hours. The mini is the same idea, shrunk until it holds a phone, a card case and a lipstick, and nothing you could regret leaving at home.

The 20 cm bags below are all pre-owned, so read condition notes like a contract. The pale Bleu Glacier in Epsom is the one I would pair with a charcoal wool coat and gray trousers this month. The Tricolor Epsom, in blue, brown and green, is for people who want a neutral outfit to have one loud detail. The Noir is the quiet answer, and the Etoupe in taupe-gray looks right against a camel knit.

For color, look at the Rose Pourpre in Chevre Mysore, the Terre Battue with gold hardware, and the Capucine, an orange-red that makes a black turtleneck look intentional. Before you commit, ask for the date stamp, look at the corners and edges, and check that the strap and turn-lock come with it.

Hermès put the Kelly name on a few smaller shapes, and the clutch versions are the easiest to carry in October, when your hands are already full of coat sleeves and a coffee. The Kelly Pochette keeps the turn-lock flap and a small handle. Neither shape pretends to be a handbag you load up.

The Swift leather in this group is soft and a little matte, so it sits against a wool or knit dress without competing. The Pochette in black is the one I would wear to a dinner, tucked under an arm with a slip dress and tights. The gray Pochette is for jeans and a blazer. The blue Swift Pochette works if your coat is neutral and you want a single color near your hands.

For brighter picks, the Rose Azalee exists in both shapes: a Kelly Cut with gold hardware and a Pochette, also with gold. The Jaune Poussin Pochette in bright yellow is a good one with an all-gray outfit. The Gris Asphalt Kelly Cut, a gray with gold hardware, is a dressier option for anyone who likes a metallic note.

Check the leather first. Look along the folds and the corners of the flap for scuffs or color rubbed away, and open the turn-lock to see if it closes cleanly. Look at the stamp, too, which tells you the year of making.

What I would skip: a clutch with no way to carry it hands-free if you plan to walk across a city. Choose the Pochette with a handle, or accept that your hand is busy.

Sellier and Retourne are the two ways a Kelly gets built, and the difference matters more at 25 cm than anywhere else. Sellier bags have crisp edges and a rigid silhouette, with the seams stitched on the outside. Retourne is softer, more casual and less structured, which tends to suit everyday use. Once you know that, a Kelly 25 listing tells you what the bag will do on your shoulder.

The Sellier Lime in Epsom with gold hardware is the stand-out here, a lime yellow that still looks sharp against navy. The Epsom Kellys, including the dark Gris Asphalte, the green Vert Yucca and the blue and gray Bicolor, hold a shape better than most. Epsom is the leading choice for Kelly Sellier bags because it keeps its lines.

The Retourne in Beton Togo, a soft concrete gray with palladium hardware, is the opposite mood. Togo is the leather I would reach for if I wanted the bag to slouch a little with a trench or a knit set. The Craie Togo is chalk white, so it is a bag for a day with no rain in the forecast. For something more playful, the Menthe Swift in bright mint and the two-tone Bubblegum and Purple Swift both come with a strap.

When you inspect a 25, check that the lock, keys and clochette all come with it, and look at the four feet on the base for wear. Compare the corners under bright light.

What I would skip: the palest colors if you commute on a crowded train. They show every bit of dye transfer from denim.

The Kelly 28 is where the color and the leather get bolder. It is a little larger than the 25, with room for a small umbrella and a paperback, so it suits a day of errands that turns into dinner. The pink Clemence, the vivid Bleu Electrique Togo and the purple Anemone Epsom are all Kelly 28 bags, and each is a good match for an all-black or all-gray outfit.

Then there is exotic skin. The Retourne 28 in Malachite matte alligator, a deep green with gold hardware, is from 2016 and will look best with brown suede and a cream sweater. The Sellier 25 in Rose Pourpre shiny Niloticus crocodile has tonal stitching and a clochette with lock and two keys. The Kelly Pochette in Bleu Electrique shiny alligator is for evenings. The Bleu Colvert Kelly Cut in Niloticus crocodile is a limited edition, a smoky blue-green that I would keep with navy and olive.

The Kelly 20 Sellier in Rouge Vif ostrich carries a 2003 stamp. Ostrich has a dotted quill pattern, so look at it in daylight and check that the pattern is even across the front and the flap.

Exotic bags need papers. Ask for the paperwork where it exists, check that the scales or quills look even, and look for dryness or color loss at the edges. Take the strap off the bag and look at where it attaches.

What I would skip: bright exotics for muddy weekend plans. They ask for a coat that is clean and a day that is dry.

A vintage Kelly shows its age in the stamp. Hermès marks each bag at the end of the process, so the date and the artisan can be traced, and with the older ones I would check the stamp before anything else. The box calf Kelly 28 with a U in a circle is stamped 1991, and the Burgundy Box Calf carries the stamp I, 1979. The 1981 Rouge H Kelly 35 is a bigger bag, an easy match for a long wool coat and tall boots.

The Tri-Color Sellier 32 has rigid lines, and I like it with a gray flannel suit. The black lizard Sellier 28 from 1990 comes with padlock and keys. The lizard bags in 20 cm, blue Saphir from 1994 and the red Rouge Vif from 1993, both come with a dust bag and strap, and they are the small ones. Among those, look at the handle size and the depth against the newer 2016 version, because the older shape is a little different.

The Kelly Pochette in black Swift with palladium is the simplest way into the shape.

Before buying, look at the leather around the handle and the corners, where older box calf can dry and crack. Check the hardware for pitting, and ask whether a strap is included, since the Burgundy 28 comes without its detachable one.

What I would skip: a bag with a replaced lock if it is described as original. Ask for clear photos of the lock and the keys.

If I were choosing, I would start with the 20 cm bag and decide on construction before color. The Sellier version is the one with edges you can feel, and the 20 II from 2016 has a smaller handle and less depth than the original, which is why it sits flatter on a coat. Then I would pick the leather that matches my weather: Epsom for rain and structure, Swift or Togo if I want softness.

After that, I would read the condition line twice and ask for the stamp, the strap and the hardware. In a pre-owned listing, a clean strap and clear stamp tell you more than a nice photo does.

Grace Kelly held hers up for a camera to hide something. I would hold mine out front, with the lock showing, on purpose. If you want to keep browsing, I also put together Gucci Perfume, Starting From a Scarf Made for Grace Kelly and Hermès Kelly Bag.