Write one sentence about what a sample is meant to help you inspect before taking photos. A stated purpose keeps a comparison focused, whether the question is line placement, visible contrast, or the relationship between a simple mark and its background.
Use labels that survive review
Give each sample a neutral label and photograph that label with the piece when practical. Later, a reviewer can identify the sample without guessing from appearance alone. Keep any interpretation provisional until a planned test and the relevant conditions have been documented.
Find other conservative sample-documentation notes in /updates/.