In 1963 A.M. Cassandre designed the YSL monogram for a house that Yves Saint Laurent and Pierre Bergé had founded in Paris only two years earlier. Cassandre also designed playing cards and scarves for Hermès, so he knew how to make a few letters carry a whole brand. Those stacked initials are why a YSL clutch reads from across a room even when the bag itself is plain.

I like the house because it began with a point of view. The first collection came in January 1962, and by 1966 Le Smoking had put women in tuxedos and Rive Gauche had made ready-to-wear a real idea. When Hedi Slimane later dropped "Yves" from the ready-to-wear name, the monogram stayed on the accessories, and Anthony Vaccarello has been creative director since 2016. The clutch is where that history gets small enough to carry in one hand.

The envelope is the shape to know, so begin there. The Cassandre Large Envelope Pouch comes in a run of finishes I would happily live with: light cumin suede for brown tailoring, zinc grey lambskin for everything else, dark ruby shiny leather for a black dress that needs a push, and natural raffia with brick trim for summer linen. The Cassandre Matelassé Flap Pouch in cream chevron quilting is smaller, at 21 by 16 centimeters, and the slim wrist strap means your hand is free at a party. The olive grey grained envelope is the quiet one, and I would carry it with a camel coat.

Practical tip: the large pouches measure about 29.5 by 18 centimeters, which holds a phone, cards and a lipstick without bulging. Close the magnetic flap in the fitting room and make sure it lies flat with your things inside.

The Kate began as a rectangular bag with a gold YSL monogram, and the clever part is that it becomes a clutch the moment you detach the strap. That one detail explains this whole group: each bag here is a clutch that can also hang from a chain when your hands are busy.

The black patent Kate has a removable gold chain and a high shine that looks sharp against denim in daylight. The dark beige grain de poudre Kate is softer, with a textured grain finish. The small Cassandre chain pouches, at 19 by 12 centimeters, come in dark cork lambskin, caramel cognac suede and light musk lambskin, and the chain tucks away when you want a hand-held bag. There is also a natural raffia and brick version for warm weather, and the dark red wine quilted zip wristlet, which is the smallest of all.

Try this before you commit: put on the coat or jacket you wear most and carry the bag by the chain, then by hand. If the chain digs through a thin sleeve, you will leave it at home. Check that the stowed chain does not rattle inside the bag, and run a thumb over suede to see if it marks.

What I would skip: the 19 centimeter pouches if you carry a full-size phone and a wallet, because you will end up carrying them in your jacket pocket instead.

Slim black pouches are the clutches that get used most, because they go with everything and weigh almost nothing. This is the family I would point a first-time buyer toward.

The Uptown Pouch in black patent leather measures 27 by 16 centimeters and only 2 centimeters deep, so it slides flat into a tote. The Uptown in natural canvas with brown leather trim and gold YSL initials is the relaxed version, and I would take it to a weekend lunch. The black grained Uptown clutch has a pointed flap that looks smart with a suit. Then there are the Paris pouches in oil green patent and black lambskin, with diamond quilting and a snap button. For something with a strap, the black chevron quilted zip pouches carry a wrist strap, and the Bijou pouch has a jewelry-style chain.

Test the flap and the edges. Patent leather shows every scratch, so tilt it under a light and look at the corners, and open the zip or snap ten times to feel whether it catches. Zipped pouches hold more than flap clutches since nothing can fall out, which matters on a crowded train.

What I would skip: oil green patent if your wardrobe is mostly neutral. It is a lovely color, but black will get carried far more often.

Evening clutches are a different job from the day pouches. They are made to be held, photographed and put down on a table next to a glass, so shape and hardware count for more than capacity.

The Daria minaudière in black shiny leather is a hinged case with a metal ring closure, 26 centimeters wide and only 1 centimeter deep, so it holds a card and a lipstick and not much else. The Midnight small clutch and the large smooth leather clutch have the embossed Saint Laurent Paris signature and a thin silhouette that tucks under an arm. The black and bitter cocoa satin soft clutches have a hammered Cassandre charm and a zip, and the black velvet Kate has a chain strap with cabochon links. For something harder, the hammered gold-tone brass Martelé clutch and the woven Tresse brass bag are almost jewelry.

Handle the hardware before you buy. Open and close the ring or kiss-lock closure a few times and listen for a clean click. Hold a brass piece up to the light and look for dents beyond the intentional hammering.

What I would skip: satin if you will carry it outdoors in wet weather, because it marks. Choose the leather case or the brass.

Everything in this last group is pre-owned, and I want to say that plainly. These are previously carried Saint Laurent bags, each with a condition grade, and that changes how you shop: you are buying a particular bag, not a new one off a shelf.

The grades here run from Very good to Excellent. The Classic Monogram Clutch in blush neutral leather and the black chevron quilted envelope with a wristlet strap are both graded Excellent. The black Monogram Tassel Clutch, the beige Monogram Envelope Clutch and the three Uptown pouches, in navy croc-embossed leather, natural raffia and pale gray smooth leather, are all graded Great. The bright pink Belle de Jour in large leather is Very good, and it is the one I would pick if I wanted a bag to be the outfit.

Here is the authenticity check I would always make: find the stamped serial number or label inside the bag, and ask for any papers or box that came with it. Then go over the condition. Look at the corners for rubbing, the edges for cracked paint, the gold YSL letters for flaking, and the lining for marks. Raffia frays at the edges first, and croc embossing can crack where it folds.

What I would skip: a Very good bag when you want something to look unused. Go for Excellent and spend your time on the corners.

If it were my bag, I would decide by evening or day. For day, the zinc grey or cumin Cassandre envelope, because the monogram is the only decoration and it goes with a jacket. For evening, the black patent Kate, since you can drop the chain for a night out and put it back on for the walk home.

If you are shopping pre-owned, check the serial, the corners and the closure in that order, and choose a bag graded Great or better. A good older YSL clutch is still doing what Cassandre's 1963 monogram was drawn to do: tell people whose bag it is from the other side of the room, without a word. If you want to keep browsing, I also put together Card Holder and Chanel Wallet Guide.