An interesting topic of the author/illustrator career path! Although I found the reality is a bit more complicated than simply getting double advance and double royalty. Below were my impression from limited conversations with other author/illustrators, my agent, editors, and basically anyone I can ask questions about author/illustrator.
-
It might be easier to sell a book I both write and illustrate, if I have already illustrated a couple of books, or have some kind of publishing experience points. It would be a bit easier to enter the industry aiming for getting an illustration gig first, and keep writing on the side in the beginning.
-
Sometimes, you might be offered low advance for author/illustrator book, lower than an illustration only gig, especially when you doing your first one. Publishers are not willing to invest a lot to an unknown artist, even though they make an offer. So you are not always getting the double amount of money for the advance.
-
Sometimes, you spend double amount of time, if not more, to do an author/illustrator book.
I think author/illustrator path is indeed more sustainable for an artist long term, if you enjoy creating your own stories (which I do, very much). But in the beginning of the career, it can feel a lot harder, a lot more demanding, and even less income. You also need to pour in as much time learning the art of writing as well as learning illustrating. I started writing on the side over the last couple of months, and I found it overwhelming sometimes, but I also enjoy the process of learning writing, almost as much as learning how to illustrating.