Letter jackets tend to spend a lot of time in the closet, where, after several years, the sleeves begin to accumulate a sticky film that never seems to go away. Of course, you could take the jacket to a dry cleaner, but that can be costly. You can, however, attack the sticky residue at home, with products you probably already have, and save yourself some money.
Things You'll Need
Mild dish soap
Leather spray cleaner
Dampen a sponge, and add a bit of mild soap. Since most letter jackets are a made of processed leather with a shell coating, the soap will not damage the jacket.
Gently wipe the sleeves of the jacket with the sponge. Don't scrub too hard, but you can rub off spots.
Use a clean, damp sponge or cloth to wipe down the sleeves two or three times, getting rid of all traces of the soap on the sleeves.
Dry the jacket with a dry cloth as soon as you are finished rinsing the sleeves. Repeat these steps if a slight sticky residue is still left on the jacket, but the jacket should feel smooth again.
Use leather spray cleaner and a rag to wipe the jacket sleeves every couple of months to prevent any sticky residue from coming back. Put the jacket in a vacuum-sealable bag if you plan on keeping it in storage for a longer period of time.
Stay away from alcohol, mineral spirits or turpentine cleaners for your jacket. Also do not use wax, silicone or other leather preparations.