Then write down some details of your painting, such as the texture of a piece of paper.
These are absolutely impossible for them to copy.
Then write down some details of the painting.
Remember to ask for the receipt.
After you frame it, you can compare the details to see if there is anything wrong, and then touch the painting. If he scans a document for you, it will be different.
If you are still not sure, ask an expert to do an eye examination for you, but generally speaking, this step is almost unnecessary.
Because if he copies an identical one for you by hand, the labor cost will be several thousand yuan, and there is a risk of breaking the law. The cost is so high, I don't think it's cost-effective, unless your painting is a peerless treasure before the Ming Dynasty.
I'm telling you, he has another shop. If there is a problem, he won't admit it. You can take the receipt to the court to sue him. I think auctioning his shop should compensate you for your loss.
My theory should be foolproof. The most important thing is to find a regular watch painting shop with complete procedures.