What is a "Trapped Dial"? It is a Wheel Chart in book-like construction. A turnable wheel is hidden between front and back covers. Add a cover and bind in additional pages to create a memorable and attention-getting Brochure Style Wheel Chart.
What is a Volvelle? A volvelle (French, meaning to turn) is a paper disc that, when rotated, can be used as a tool for calculations or other less scientific purposes.
Here are a few examples of trapped dial brochures and volvelles. Click for a closer look. Let us know if you need to see samples or want to brainstorm your idea.