The two happiest days of my life, the day we bought the embroidery machine, and the day we sold the machine!
We got burned by a "former" customer. They had a logo that was drawn on a piece of paper. We had to scan it and clean it up before digitizing it for the machine. They wanted a .jpg of the logo so they could put it on their desktops. We complied with 72 dpi files. In the middle of the run, they want us to stop production since they found someone else who will do it cheaper. They did pay for what we had finished, and wanted the digitized file as well as the vectorized file for their new company. I told them that the digitized file was of our property since it was a file we developed and had put numerous hours into it's cleanup.
Long story short, I had a disclaimer on my estimates that stated that all edited or developed artwork was property of the company. Purchase of the artwork would be negotiable at the beginning of the job. I quoted the price of the artwork $10,000 just to deter them. They got the finished product, the original paper artwork, and the 72 dpi files. They're new embroiderer charged them twice as much as I did to digitize the artwork. Where's the savings.
It's important to have some type of disclaimer to protect the hours one can spend working on artwork. Especially for folks who develop the stuff fresh out of their imagination! I recommend you find a good friend who happens to be a lawyer.