Leather jackets and shirts last a long time and have a lot of wear in them because leather is thick and durable. Thus, leather will often stain and become unwearable because the actual leather shirt or jacket rips or tears. One way to keep the leather lasting longer is to remove sweat stains on the collar as soon as you notice them. This will prevent it from seeping deeper into the leather where it may be harder to remove. There are two processes for cleaning leather depending on the type of leather you have. Unfinished leather, such as suede or nubuck, has a nap, while finished leather is smooth.
Place the shirt or jacket on your cleaning space and spread out the collar so that it is flat. This will allow you to clean it easier.
Mix 1 cup vinegar with 2 cups linseed oil. Vinegar will neutralise bad odours and will help remove stains, while linseed oil will condition the leather. If the leather is unconditioned it will appear dry and may crack.
Apply the cleaning solution to the jacket with a clean cloth. Rub the cloth in a circular motion to loosen the stain.
Leave the solution on the jacket for several hours or overnight. This will allow it to fully penetrate the stain.
Buff the solution off in circular motions with another clean cloth.
Apply a small amount of toothpaste to the stain with a toothbrush if the stain is still visible.
Gently brush the toothpaste into the stain until you've removed it.
Wipe up the toothpaste with a damp cloth.
Apply acetone to a damp cloth if the stain is still visible. Dab the stain with the acetone until you've removed it.
Rinse the leather with a water-dampened cloth.
Dry the leather completely.
Mix 1 cup of water with 1 tbsp liquid dish soap until a generous amount of suds form.
Apply only the suds to the stained collar. Work the suds into the collar, but do not apply any water to the suede. Repeat the process until you've removed as much of the stain as possible.
Rub an eraser over the stain. This will remove the tip layer of the suede and will therefore remove the stain.
Gently brush a nail file over the stain if it is still visible. Be careful not to rub too hard as you could rub a hole in the suede.
Brush the entire suede jacket or shirt with a suede brush. Suede brushes will help restore the nap and work out little piece of dust and dirt.