The paper is structured into three distinct sheet types depending on its placement in a form stack:
1. CB (Coated Back): The Top Sheet. It is an ordinary writing surface on the front, but its underside is coated with millions of microscopic, pressure-sensitive gelatin or synthetic capsules filled with invisible dye.
2. CFB (Coated Front and Back): The Middle Sheet(s). Essential for triplicate (3-part) or quadruplicate (4-part) bank forms. The top side has a reactive clay layer to absorb the image from above, while the bottom side has micro-encapsulated dye to pass the impression to the next page.
3. CF (Coated Front): The Bottom Sheet. The final copy layer. Its top surface features the reactive clay coating to lock in the final duplicate, while its back remains uncoated.