The side of your bag that faced the window is noticeably darker than the side that sat in the shade. Or the opposite: the flap has gone pale while the rest is still deep in colour. A leather bag faded by sun or light is almost never damaged beyond use, but it is a difference that doesn't simply reverse itself. Which way it goes depends on the leather.
The short answer: vegetable-tanned leather darkens under UV light, dyed and chrome-tanned leather lightens. The first is part of the material and is called patina, and it only looks bad when it happens unevenly. The second is genuine colour damage. Both can be evened out, but touching up with leather dye only makes sense on chrome-tanned leather.
Why has your leather bag faded, and which way?
Vegetable-tanned leather is full of tannins from tree bark: oak, chestnut, mimosa, quebracho. Those tannins react to ultraviolet light and oxygen and darken as a result, much the way a cut apple browns. A new cognac bag is honey-coloured, and after a summer on your shoulder it's chestnut brown. That process doesn't stop, it just slows down. Friction and fat from your hands speed it up, which is why handles and flaps always run ahead of the rest.
Chrome-tanned leather doesn't have those tannins. Its colour comes largely from pigment or aniline dye instead, and dye fades under UV. A black chrome-tanned bag turns greyish after a few summers, a red one goes orange-pink. On vegetable-tanned leather that's also been dyed after tanning, you sometimes see both effects at once: the leather underneath darkens while the dye on top lightens. How to tell the two leather types apart is covered in our article on vegetable-tanned versus chrome-tanned leather.
| Vegetable-tanned leather | Dyed or chrome-tanned leather | |
|---|---|---|
| Direction | Gets darker and warmer in tone | Gets lighter, paler, sometimes grey |
| Speed | Visible within weeks, never really finished | Visible after months, speeds up in strong light |
| Is it damage? | No, this is patina, uneven fading is the problem | Yes, the dye is breaking down |
| Evening it out | Let the paler side catch up with light and time | Only by re-dyeing |
| Touching up with dye | Not advised, it covers the grain and stops the patina | Possible, with pigment dye in a matching shade |
Preventing an uneven leather bag colour
With vegetable-tanned leather, fading (or rather, darkening) can't be prevented, and you don't want it to be. It's the reason a ten-year-old bag looks better than a new one; our article on patina explains how that works. What you do want to avoid is one side going through the process on its own. A bag left on a chair with the same side facing the window for months ends up with a pale side and a dark side split by a sharp line. That line is the problem, not the colour itself.
The rules are simple. Store a bag you're not using in a wardrobe or a cotton bag, not on the windowsill. Don't leave it in the car: on a parcel shelf behind glass, the temperature climbs above 60 degrees in summer and most of the UV light gets straight through. Two weeks there does more than a year on your shoulder. And if a bag does have a fixed spot by a window, turn it a quarter-turn every week. A belt such as the Oden is best hung by the buckle in a wardrobe rather than draped over a chair in the light, otherwise you end up with a bleached loop and a darker rest of the strap.
Leather balm with a UV filter is sold as the answer. It doesn't do much of anything. A thin layer of wax keeps out some moisture and dirt, but not ultraviolet light; for that you'd need a thick, opaque coating, and you don't want that on leather. Ordinary leather balm works just as well, and what you save is a few pounds.
Leather bag faded: evening it out or touching up
With vegetable-tanned leather, you use the same light that caused the problem. Leave the bag outside in the shade for a few days, or indoors by a north-facing window, with the pale side towards the light. Indirect daylight has enough UV to let the lagging side catch up without pushing the darker side much further. Check it daily. On a cognac bag such as the Lorne, the line usually starts fading within three to five days; it only evens out completely after a few months of normal use. A thin layer of leather balm beforehand helps, since fat speeds up the darkening and deepens the tone slightly.
I wouldn't recommend leather dye on vegetable-tanned leather. Pigment dye lays an opaque layer over the grain, so the leather can no longer breathe, and the patina stops right where you've dyed it. A year later you're left with a bag that's coloured evenly everywhere except the touched-up spot. Accepting it and letting it patinate is nearly always the better answer, however unsatisfying that feels in the first week.
With chrome-tanned or dyed leather it's a different matter. There the dye breaks down and doesn't come back, so touching it up is the only option. Clean the surface and remove any grease, use a leather dye or colour restorer in a matching shade, apply it in thin coats with a sponge and feather the edge into the undamaged area widely. Test on the underside first. Don't expect miracles on a bag that's spent three summers in the sun; the dye is degraded deep down by then, and the result is often a shade that's almost, but not quite, right.
If the sun has also left the leather dry and stiff, which often goes hand in hand with fading, deal with that first using the steps in our article on dried-out leather, and only look at colour afterwards. Fed leather takes up colour and light more evenly than dry leather does.
One thing often mistaken for fading: a bag rubbing colour off onto a pale coat or white trousers. That's not UV damage but excess dye or too much leather balm sitting on the surface, and it's common in the first few weeks with dark vegetable-tanned leather. A few rubs with a dry cloth usually sorts it out. If the bag itself gets lighter where it rubs against your coat, that's wear on the dye layer instead, and that's a different problem entirely.
