A writer found some clip art they’re interested in using in their book, but they also had concerns. The terminology is “Royalty-free clipart for commercial use.” Is it safe to use?
First, let me say that I am not a lawyer, and this is not legal advice.
Given that, in my opinion, the phrase gives you the protection you seek for this clip art image. However, I recommend going to a reverse image search engine, such as TinEye.com. You can upload the image in question, and they will check their index to see if anyone claims ownership.
If it’s okay to use, keep a record of the results, and then consult a couple more sites just to be sure. (Just search for “reverse image search engines“ for other options).
If it’s not legally permissible for you to use, then buy a royalty-free license (not an editorial license) or find alternative artwork. If you buy a non-exclusive license than others can use it as well. A more expensive exclusive license means only you can use it.