Leather is a natural material that requires special care to keep it looking and feeling its best. However, not all baseball glove leather care products are created equal. Some products can actually damage leather. That's why it's important to know the contents of leather care products before you use them. Here are a few things to look for:

pH: The pH of a leather care product is important because it can affect the way the leather reacts. Products with a high pH are alkaline, which can damage leather. Products with a low pH are acidic, which can also damage leather. The pH of leather is 4.5 to 5.0. The ideal pH for leather care products then is about 5.
Oils: Leather conditioning products contain oils. Some are good for leather, other’s can actually cause damage. The good oils help keep the leather supple making the glove easier to use. They also protect leather from moisture and dirt. However, bad oils with a high iodine index (Olive oil, Neatsfoot oil, Mink oil) can become rancid over time. Rancid oils can damage leather, so it's important to use products with oils that have a low iodine index such as Mitt-Spit Glove oil.
Other ingredients: Some leather care products contain other ingredients, such as solvents, waxes, and detergents. These ingredients can also damage leather.

Be aware of what you’re putting on your glove. Ask questions. Don’t just fall for the marketing spin. If you're not sure what's in a leather care product, it's best to err on the side of caution and avoid using it. There are many safe and effective leather care products available, so there's no need to risk damaging your glove.

Here are some of the damage that can be done by using the wrong product on leather:

Glove can become dry and brittle.
Glove can become discolored.
Glove can crack or split.
Glove can feel clunky, overly heavy.

The Potential of Rancidity and the Damage it Can Cause When Using Oils with a High Iodine Index

Rancid oils can damage leather by making it brittle and cause cracking. They can also discolor the leather and make it look old and worn. And of course have an unpleasant odor.

The iodine index is a measure of the potential for oil to turn rancid. Products with a higher iodine index, like Neatsfoot oil, have a greater potential so they will be more likely to turn rancid. Products with a lower iodine index like Mitt-Spit glove oil will be less likely to turn rancid.

If you're using a leather care product that contains oils, it's important to store it in a cool, dark place. This will help to prevent the oils from turning rancid.

If you're not sure what kind of leather care product to use, it's always best to consult with a professional. They can help you choose the right product and show you how to use it properly.

If you're not sure whether a leather care product contains the correct oils, it's always best to check the label. If it doesn’t list the contents then check with the manufacturer about that oil’s Iodine Index. You can also do your own research. Google it.

By following these tips, you can help to protect your leather glove from damage and keep it in the best possible condition improving your odds of playing well.