Like all materials, leather gets old. With age comes some deterioration and fading. If the leather is being used on furniture, it will lose its original luster and start looking ratty and dull. When this happens, it doesn't mean it's time to replace the furniture. It simply means that you are in need of a leather restorer.
Each of the commercial leather product companies have different versions of leather restorers. Some companies even sell leather conditioner and mark it as a restorer. But when most companies talk about restorers, they are talking about re-coloring or dyes, which bring your leather's faded color back to its original state while protecting and conditioning it as well. You know you are in need of a restorer when your leather furniture is no longer returning to its original beauty and color after being cleaned, polished, and conditioned.
The first thing you need to do is to find a leather re-coloring balm or leather dye which matches your leather's original color. You can ask a sales representative to help you choose the right color. There are also some products which are colorless, and are supposed to be able to re-color the leather without dye. These may work well for you too, especially if the leather is of a lighter color.
Next, apply the re-coloring product or dye to the leather with a soft cloth. Most of these products already have a conditioner worked into the solution. If the one you purchased doesn't have conditioning features as well, you may have to apply conditioner to the furniture, but you will have to wait till the dye dries out or is absorbed completely. Also keep in mind that after applying the re-coloring product or dye, you shouldn't sit down for a while.
Make sure you buy a product specific to your type of leather and specific to its finish. Some antique leather furniture will need a different product, while different finishes, like chesterfields, will also need a different type or restorer.
After applying the dye, use a finishing kit to seal and protect the leather's color. This is often a spray-on product and it can be applied shortly after the dye has been used. If there are certain areas of the furniture which have scuff marks even after the dye, use a damage restorer before spraying on the finishing kit.
A leather restorer can help you keep your leather furniture for longer periods of time, renewing it like you're starting from scratch or like you've just bought it.. It's ability to get rid of scuff marks and scratches and to make your leather look brand new again!