Summary: Restore dried-out leather by conditioning it in several thin layers over a period of days, not in a single treatment. Leather with actual cracks in the grain cannot be fully restored, but it can be stabilized.
How leather dries out
The oils introduced into leather during tanning gradually disappear due to heat, sunlight, water, and use. Without these oils, the collagen fibers can no longer move smoothly past one another. They rub, harden, and eventually break.
The most common causes are a bag that has been left in a hot car for months, storage next to a radiator, an attic with large temperature fluctuations, or simply years without maintenance.
Assess it first
Determine what stage the leather is in before you begin.
Stage 1, dull and stiff. The leather feels papery and has lost its sheen, but the surface is intact. This can be almost completely restored.
Stage 2, fine hairline cracks at the folds. When you bend the leather, you see faint lines appear. Conditioning still helps considerably here, and the cracks will become much less visible.
Stage 3, open cracks in the grain. The surface has split. This cannot be reversed. However, you can stabilize the leather so it does not crack further.
Stage 4, crumbly and powdery. The leather crumbles when you squeeze it. This is usually a sign of chemical degradation and cannot be saved.
What you need
- A soft, clean cotton cloth, preferably two or three
- Mild leather cleaner or lukewarm water with a drop of neutral soap
- A neutral leather balm or conditioner suitable for your leather’s tanning process
- For severely dried-out leather: a leather grease based on lanolin or beeswax
- Patience, because this is a process that takes days
Do not use olive oil, baby oil, or skin cream. They eventually go rancid, cause stains, and soak in unevenly.
Step by step
- Clean it thoroughly first. Dried-out leather is full of embedded dust. Wipe the surface with a slightly damp cloth and work in small sections. Let it dry completely for at least a few hours.
- Test the product. Apply a small amount to an inconspicuous area and wait overnight. Severely dried-out leather absorbs product readily and may become significantly darker. This is usually permanent, so you want to know how much to expect.
- Apply the first thin layer. Put a small amount on the cloth and work it over the entire surface in circular motions. Do not rub it in until it shines; apply only an even, thin film.
- Let it absorb for a full day. This is where most people move too quickly. The leather needs time to truly absorb the product.
- Repeat two to four times. Keep each layer thin and wait a day each time. You will notice that the first layers almost disappear immediately and that the leather absorbs the product more slowly later on. If product is still sitting on the surface after a day, the leather is saturated and you should stop.
- Work the folds extra carefully. While the product is absorbing, gently move the leather back and forth at the folds so it truly reaches the creases.
- Buff it. Use a clean, dry cloth to remove the remaining residue and restore the sheen.
With open cracks
Condition the leather as described above, but do not expect the cracks to close. What you can achieve is making the edges of the cracks supple again so they do not split further. For visible repair, you can use a leather repair paste applied into the crack and smoothed out, but the result will remain visible.
For valuable pieces, a leather specialist is the better option. See also Scratches and worn spots: repair them or embrace them?.
Prevention is considerably easier
Drying out can be almost entirely avoided with a routine of conditioning twice a year and storing the leather sensibly: at room temperature, out of direct sunlight, not in plastic, and not next to a heat source.
See Conditioning leather and What is the best way to store a leather bag?.
