@Barb H Sorry to have missed your tag last week! Thanks for tagging me in again. 😊 I would say that it sounds like your images are decorative, so in that case, I wouldn't worry about including image credits below each one—instead, yes, a copyright page credit is totally fine! I think you're all set to go with your current draft ("All images used in this book are licensed from DepositPhotos under a Standard License that permits commercial use.")—no need to worry about the "royalty-free" language or anything else. Since they don't require a credit line, you can really say whatever feels most appropriate to you, provided that it's accurate. And just so you're not worrying, I want to reassure you: Since DepositPhotos doesn't require a credit line, that means that no one does and there's really no huge pressure to get this perfect! Including this credit line is really just about looking professional, nothing more. As for how to write the company name, again, I wouldn't stress about it, but generally the Chicago Manual of Style recommends that one uses the styling that the company itself uses, so in this case, that would be DepositPhotos (or depositphotos.com). That being said, it's definitely no big deal, so if a different styling feels more appropriate to you, that's fine!