A paper characteristic curve is a graphical representation showing the relationship between exposure and resulting image density on photographic printing paper. Each brand and type of paper has its own initial curve, reflecting how it responds to light and development.
The shape of the curve can be influenced by factors such as the choice of developer, development time, temperature, and toning processes. Understanding the paper characteristic curve helps photographers control contrast, tonal range, and overall print quality, ensuring consistent and predictable results in the darkroom.