Dry down refers to the change in density or appearance of a photographic print as it dries after processing. Many prints, especially black-and-white or fibre-based prints, appear slightly lighter when wet and then darken to their final tone as the paper dries completely.
Understanding dry down is important for photographers to judge final contrast, exposure, and tonal balance accurately. Anticipating how much a print will darken helps ensure consistent results and avoids over- or under-exposure during printing.