The edge is the one part of a leather piece that cannot hide how it was made.
Every leather object starts as a flat hide cut into panels. Wherever a blade passes through, it leaves a raw cross-section: the grain on one face, the looser flesh fibres on the other, and a band of exposed fibre ends in between. Left alone, that cut edge is soft, slightly fuzzy, and open. It takes on moisture and dirt, and with handling the fibres begin to lift and fray. On a wallet or a card case the edge is also where the hand lands first, so an unfinished one is felt before it is seen.
There are broadly three ways to deal with it. Fold the leather over so the raw edge sits inside the piece, which is called a turned edge. Coat it with edge paint, which seals the cut under a flexible film. Or burnish it, which seals the edge using the leather itself. This piece is about the third.
Burnishing is friction applied to a cut edge until the fibres compress and bind into a single smooth surface. Nothing is added that does the sealing for it. A compound or a little water helps the process along, and a coat of wax protects the result, but the finished edge is the leather's own fibres, packed down tight.
The sequence is broadly the same across most workshops, even where the tools differ.
The edge is bevelled first. An edge beveller shaves the sharp square corners off both faces of the cut, leaving a profile that can be rounded rather than one that stays a flat rectangle. Where several layers are stitched together, they are trimmed and sanded flush so the edge reads as one thickness rather than a stack.
The edge is then sanded, usually through progressively finer grits, to take out tool marks and even the surface.
Next comes moisture or a burnishing compound. Water alone will work on a good edge. Traditional workshops used gum tragacanth, a plant gum. We use Tokonole, a water-based burnishing agent made by the Japanese company Seiwa.
Then the slicker. A slicker is a hand tool, traditionally wood, bone or glass, with grooves cut to suit different leather thicknesses. The edge sits in the groove and the slicker is run back and forth along it, quickly and with steady pressure. The friction generates heat, and heat and pressure together compress the loose fibres into a firm, closed surface. Workshops working at volume use a motorised burnisher, for the same reason most stitching moved to machines. It is quicker. The principle is the same.
Finally, wax. A wax finish over the burnished edge adds a further layer of resistance to moisture and gives the edge its final sheen.
The sequence often runs more than once. Dampen, slick, let it dry, go again. A good edge is built in passes rather than in one go.
Burnishing works best, by some distance, on vegetable-tanned leather. Veg-tan is firm and fibrous, and its fibres respond to friction and compression by binding together and holding the shape they are pressed into. That is the property burnishing depends on.
Chrome-tanned leather behaves differently. It is softer and more pliable, which is often exactly why it is chosen, but that softness works against burnishing. It is hard to build consistent friction on an edge that gives under the tool, and the fibres do not bind in the same way. Some makers do get a passable result on certain chrome-tanned leathers with the right compound and a lot of patience, but the finish is rarely the hard, closed edge veg-tan gives, and it is not the method most makers reach for. Chrome-tanned edges are usually painted or turned instead.
So the finishing method is not really a free choice. The tannage of the leather largely settles it before any tool touches the edge. It is the same point made in our earlier piece on veg-tan and PU leather: the material decides what is possible later.
Read: Veg-Tan Against PU LeatherEdge paint is not a lesser finish by default. Applied well, in several thin coats with sanding between them, a painted edge is clean and consistent, and it suits leathers that cannot be burnished. It is the standard finish across much of the industry, partly because it is fast and repeatable at volume.
The difference shows up later. A paint film sits on top of the edge. With enough flexing and abrasion over the years it can crack or begin to lift, and once it does, the repair is to strip it back and repaint. A burnished edge has no film to separate from the leather, because the finish is the leather. It wears gradually, the way the rest of the piece does, darkening and softening with handling, and a worn burnished edge can be refreshed with the same compound and slicker that made it.
Neither finish is permanent. They age differently, and for a piece meant to be used every day for a long time, how it ages is the part that matters.
If you want to judge a leather piece quickly, run a thumb along its edge. A well-burnished edge feels smooth, firm and slightly rounded, with no ridge where layers meet and no loose fibres catching on the skin. Under light, the colour should be even and the surface should have a soft shine rather than a fuzzy matte. A painted edge also feels smooth, but often has a slightly rubbery feel, and on older pieces you can sometimes see where the paint has cracked at the corners.
An edge does not tell you everything about a piece. But it is one of the places a maker has the most room to cut corners, because it is also one of the last things anyone checks. That makes it a fairly honest indicator of how much time went into the parts nobody asked about.
The Draw, our telescopic cigar case, is cut from vegetable-tanned tooling leather and specified with edges burnished by hand and wax finished. Edge bevelling and edge finishing are recorded as separate stages in its build record, and burnishing comes last in the order of work, after every seam has been saddle stitched, so the stitched layers are finished together as a single edge. The same piece also uses a turned edge at the sleeve opening, where the lining folds over to the outside. Different edges on one object, each chosen for what that part of it has to do.
It is slow work and it does not scale well, which is the same trade that runs through the rest of the studio. An edge is one of the details that decides whether a piece wears in or wears out, and we would rather it wore in.
The material decisions behind current pieces, including how their edges are finished, go out through Material & Method, the studio's monthly newsletter. The waitlist is open now.
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