Add fine texture across the photograph. Grain can join the tones of an image and make a polished digital surface feel more tactile.
When to use it
Try it on portraits, monochrome and softly graded color. Judge it at a useful viewing size and again on your export.
How to control it
Grain controls strength. Grain Size changes the scale of the pattern; Grain Roughness changes its character.
A starting approach
Choose the scale first, then raise strength. A coarse pattern is an expressive choice, but can obscure small details at strong settings.
Combine with intention
Choose one main direction first. Compare with the effect reduced or off before adding another treatment. Check the exported photograph as well as the preview.