I wrote and illustrated a picture book a while back, decided nothing was going to come of it, and let it languish in my portfolio for years.A few weeks ago, I decided to dust it off and take another look. As expected, the illustrations are better than the words. I may revise someday, but in the meantime I started posting the illustrations on Instagram.Looking at those old Illustrations, I've come to realize they work as a picture book without words a-la, Mercer Mayer's, "A Boy, a Dog, and a Frog". Not to compare myself with the great Mr. Mayer, it's just the best example I can think of.So, here's the question: How does the copyright work for a book with no text?If I post the entire story, do I risk someone seeing it and using my story idea with their own words? Should I quit posting them? Is it too late? Am I being paranoid?
Copyright doesn't protect your work from being stolen (plagiarized.) It provides a remedy for you if it happens (suing for damages.)
You can copyright visual material like you do text.
You copyright it with the US Copyright office like you do a book.
Here's an example of a visual materials copyright listing. It's for the illustrations for The Snurtch (text by Sean Ferrell), illustrated by Charles Santoso.
Notice that the registration number start with VA, not the TX you see on books (Visual versus Text)
You might look at other illustrators Instagram accounts and see how much they post of a book. My sense is that it's a page or two, not the entire book.