Juliana S. answered 06/28/19
Expert in Adobe Photoshop, Adobe Lightroom, and Photo Retouching
To protect your work from such clients, I suggest that you draw a contract to be signed before the work starts. On the contract, you need to add specific information of what rights the client will have for the price he's paying you. There are a lot of contract samples for designers and other artists online, if you do a search. There are also books on the subject. As for locking the design from printing, you can save it as a password protected pdf if you have Adobe Acrobat on your computer.