A neutral background can make a sample comparison easier to revisit because it removes one changing visual variable. Photograph the sample, its label, and a simple reference marker in the same frame whenever practical.
Describe what the image shows
Write down the date, material identity, and lighting condition with the photograph. An image can document appearance at one moment, but it does not prove a material claim, a final setting, or a repeatable result. Keep those boundaries clear when sharing a sample note.
For more evidence-aware sample notes, browse /updates/ before filing the next image.