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How to clean old leather
Determine what kind of leather you're trying to clean.
Knowing the type of leather you have will help you select the correct cleaning product. Natural or untreated leather does not have a protective coating, while treated leathers do.
You can tell that your leather is untreated if it's soft to the touch and doesn't feel like it has a plastic coating. Untreated and natural leathers may change color after you clean them.