These small rolls of thermal paper provide a record of calculations performed on adding machines and certain types of calculators. Typically, they are narrow, with a smooth, slightly shiny surface, and are wound tightly onto a small spool. The paper is treated with a chemical that changes color when exposed to heat, allowing for the impression of numbers and symbols without ink.
Maintaining accurate records in accounting, finance, and other numerical fields is vital. This medium offers a tangible audit trail, supporting accountability and facilitating the verification of figures. Prior to the widespread adoption of digital spreadsheets and electronic calculators, these rolls were essential tools in businesses, educational institutions, and scientific settings. While their usage has declined with the rise of digital technology, they remain relevant in specialized applications and scenarios where a physical record is required or preferred.