Penelope June is a watercolor picture book series. Four manuscripts are drafted. Before a single illustration exists, the character and the palette are locked, because that's the part that breaks.
A picture book series lives or dies on whether the reader believes it's the same character in book four as in book one. Not similar. The same. Children notice this faster than adults do and they're unforgiving about it.
Most self-published series get this wrong in the same way. They illustrate book one, love it, then discover in book three that the character's proportions have quietly wandered, and there's no way back without redrawing everything.
So the reference comes before the art. Proportions, silhouette, the specific palette, and the handful of details that have to be identical every time.
Everything else is deliberately loose. A system that specifies every frame stops being a system and starts being a cage.
Silhouette first. If it doesn't read at thumbnail size, it doesn't read.
A fixed palette per book, drawn from one series palette, so the shelf looks like a set.
The short list of details that never change, kept separate from everything an illustrator is free to interpret.
This one isn't a revenue project and I won't pretend otherwise. The goal is to take something from idea to a finished hardcover I'd be happy to hand someone.
It earns its place here for a different reason. Holding a brand system tight across a catalog, when nobody is checking and there's no deadline, is exactly the discipline that keeps a company's documents from falling apart.
The expensive decisions are the ones you make by accident, early.
Send me the project that has been sitting there. I'll tell you what I'd do with it and whether I'm the right person to do it.