A Rush Fee is an additional cost applied when a client requests a quicker turnaround on their project. In the context of children's book publishing, this could involve a faster illustration process, quicker editing, or expedited printing services. Typically, this fee compensates illustrators, editors, or publishers for prioritizing one project over others, ensuring that your book meets tight deadlines. It’s essential for authors and illustrators to communicate clearly about the expectations and costs associated with rushing a project.