Let’s say you take your work to a venue (gallery, home, business, etc.) because someone has asked to see it in person. After you arrive, you’re asked to leave your art at the venue so that other people can see it. It’s fine to do this as long as you have something in writing.
Always get your art business transactions in writing! In this scenario, while you didn’t exchange money, you did agree to leave a valuable asset in the care of someone else.
The piece of paper (which might be called a loan agreement) you draw up should state your name, the title, dimensions, and value of each piece you’re leaving. Your agreement should also be clear that you retain ownership and copyright and that the venue agrees to insure the work while they have it in their possession. The art should not leave that venue without your written consent. It would be terrific if you have a photo printout of it–either attached to the document or printed on the same page.
You could also add a schedule for pickup–the deadline or date when you would like to retrieve the work.
Include a space on the document for both parties to sign.
Consider creating this document ahead of time and taking two copies with you so that you don’t have to hunt down a copy machine. You would then have two originals–one for you and one for the borrower.
What else am I forgetting?
(Note: Please consult with an attorney for your specific situation.)