It's winter and your furnace is working overtime to keep you warm. Good for you, but not so good for your leather furniture. Dry heat robs the leather of the essential oils. Overtime this can cause a the leather to become stiff and less supple. Just like your skin needs more body lotion to keep it moisturized, so does the leather in your home (or car).
We recommend using a leather conditioner to treat your leather at least twice a year. You can find a conditioner in your local stores. Just look for a product that does not contain sylicone, and preferably made with a lanoline. Keeping your leather conditioned will prevent "premature aging", and extend the life of the leather.