Leather sofas left out in direct sunlight are much more likely to develop cracks over time. The sunlight and warmth dries out the leather, leaving it vulnerable. It is necessary to place a genuine leather sofa in an area of the room that does not receive direct sunlight. If this is not possible, consider installing blackout or insulated drapes and close them when the sun is at its peak.
Humidity is also an important factor in maintaining the suppleness of leather. The air in a home is often dry, either due to climate or the use of a central heating system during winter months. This causes a leather sofa to dry out. To combat this problem, install a small humidifier in the room with the sofa. This helps put humidity back into the air and provides the sofa with the ambient moisture it needs. If there are several pieces of leather furniture throughout the house and the home is continually dry, consider installing a whole house humidifier.
Oiling a sofa reduces the appearance of current cracks and helps minimize the risk of developing new ones. Use a leather soap or oil that is intended for the particular color of leather sofa, especially if the leather is light in color. Always test the oil on a hidden area of the sofa before treating the whole piece to prevent discoloration.
Cleaning a leather sofa on a weekly basis also helps improve the surface moisture and minimizes cracking. Use a specific cleaner meant for leather furniture, or even regular furniture polish. Use a soft cloth and spray the cleaner directly on the cloth -- not on the sofa. Work it into the leather gently. Be prepared for the surface of the sofa to remain slippery for a few days after treating it.