Leather is one of the few materials where quality differences are large, visible and describable, and where the vocabulary to describe them has been almost entirely replaced by brand names.
The cut of the hide
A hide has layers, and which layer you get is the biggest single quality determinant.
Full grain is the outermost layer with the natural surface intact, including scars, insect marks and grain variation. It is the strongest part because the fibres are densest there.
Top grain has that surface sanded off to remove imperfections, then a finish applied. More uniform, weaker, and it will not develop the same surface over time.
Genuine leather, despite sounding like a quality claim, generally refers to lower layers after the top has been split off. It is real leather and it is the least of it.
Bonded leather is scrap leather ground up and adhered to a backing, which behaves like plastic and eventually delaminates.
The terms are used loosely in marketing, and the physical characteristics are checkable.
How to tell what you are looking at
Full grain shows irregular pore patterns that vary across the piece, because skin varies.
A perfectly uniform surface pattern is embossed, which means a finish was applied and stamped.
Look at a cut edge. Full grain shows a fibrous cross-section with visible density variation. A layer of pigment sitting on top of a different-coloured body means heavy surface finishing.
Smell is a real test, though harder to describe. Heavily finished leather smells of the finish rather than of leather.
Tanning
The second major variable.
Chrome tanning is fast, taking a day or so, produces soft supple leather in any colour, and accounts for the vast majority of production.
Vegetable tanning uses plant tannins over weeks, produces firmer leather that develops colour and character with use, and costs considerably more in time and space.
Neither is better in the abstract. Vegetable tanned leather is what you want for something meant to age visibly. Chrome tanned is what you want for a soft garment.
Environmental profiles differ and neither is clean — vegetable tanning uses enormous quantities of water, chrome tanning uses chemicals requiring careful handling that is not always given.
Where the money actually goes
In a luxury leather item, hide cost is a real but not dominant share.
Skilled labour, particularly hand finishing of edges and hand stitching, is expensive and slow.
Waste is enormous — cutting around hide defects on a natural material means using perhaps half of a hide for the best pieces.
And then brand margin, which at the top of the market exceeds all production costs combined by a considerable multiple.
That last item is the one being paid for at the highest price points, and pretending otherwise does nobody any favours.
Edge finishing
The detail I check first on any bag or small leather good.
A raw cut edge left exposed is the cheapest option and will fray.
A painted edge, built up in layers and burnished, takes real time and looks smooth and slightly rounded.
A folded edge, where the leather is skived thin and turned under, is the most labour intensive.
Run a finger along the edge. Rough, thick paint that you can feel as a ridge means a fast job. Smooth and integrated means someone spent time.
Stitching
Machine stitching is a straight line of identical stitches, with the thread locked by a second thread underneath.
Saddle stitching, done by hand with two needles, produces a slightly angled stitch pattern and does not unravel if one stitch breaks.
It is genuinely stronger and enormously slower, which is why it appears on a small number of items at a particular price level.
Stitches per inch is also informative — denser stitching takes longer and holds better.
The reasonable conclusion
Understanding these characteristics does not mean you should buy expensive leather. It means you can tell what you are actually getting at any price.
Some mid-priced makers use full grain vegetable tanned leather with careful edge work. Some very expensive brands use heavily finished top grain with painted edges.
The material tells you. The price tag is a much less reliable narrator.
Hardware
The component that fails first on most bags and the one least examined at purchase.
Solid brass is heavy, does not chip, and develops a patina. Plated base metal is lighter and eventually wears through to a different colour underneath.
Scratch an inconspicuous spot — plating shows immediately.
Zips are the other failure point. A handful of manufacturers make the zips found on almost everything at the upper end, and their name is stamped on the pull.
A generic zip on an expensive bag is a genuine signal about where the budget went.
Structure and lining
Whether a bag holds shape when empty depends on internal reinforcement that costs money and adds no visible feature.
Leather-lined bags cost considerably more than fabric-lined ones and are heavier, which is a real trade rather than simply better.
Suede lining looks luxurious and marks easily. Cotton canvas lining is durable and unglamorous.
Checking whether the lining is stitched in or glued tells you whether it can be repaired when it eventually tears, and glued linings generally cannot.