Artists who create commissions know one caveat with accepting PayPal: their Seller Protection doesn't cover services, so they can and will be SOL if the buyer decides to dispute the transaction. While Buyer Protection doesn't cover services either, PayPal is notorious for ruling in the favor of the buyer, so the seller needs to look into other ways of protecting themselves.
Which leads to our discussion here, of how we can leverage Seller Protection to ensure scamming buyers can't run off with the money after the service is completed -- by converting your commission service into a tangible product.
Seller Protection covers tangible products that can be shipped to the buyer, and by making a commission, you can take advantage of this by printing out your commission and mailing it to them. Right there, you have a tangible, physical item that is mailed to the buyer, and thus is covered by Seller Protection.
Adjust your commission information and terms of service to indicate the buyer is purchasing a physical, hard copy of a piece of custom-made artwork that will be mailed to them, and that they can also request an additional digital copy at their preference. Request the buyer's address in your commission forms, and when your commission is completed, mail the hard copy to them. The hard copy should have a delivery confirmation ($1.00).
Did You Know? If you're sending something overseas, and you happen to use USPS (United States Postal Service -- NOT UPS), the customs form number also functions as a tracking number. And it's free. Hohoho.
Log your delivery confirmation or customs number in a record file with the customer's information. If any of these obnoxious chargebacks happen, you now have a physical item that was shipped to the buyer as well as a tracking or delivery confirmation number.
Enjoy the Seller Protection.