When pressure is applied to the top sheet through writing or printing, the microcapsules break, releasing the developer chemical which reacts with the dye to create a visible mark on the underlying sheets. This allows for the creation of multiple copies of a document in a clean and efficient manner, without the mess and inconvenience of using traditional carbon paper.

NCR books are commonly used for creating receipts, invoices, purchase orders, delivery notes, and various other forms where multiple copies of the same document are required. They come in various formats, such as single-sheet sets or multi-part books, where each part is a different color to help distinguish between the original and the copies.