A coloured arrow helps you remember a manuscript detail, but it can become misleading when the annotated screenshot circulates without explanation. Keep a clear boundary between the reproduction and your own reading marks.
Save the source link, image identifier and any permitted unaltered reference before making a working copy. Follow the holding institution’s reuse conditions. A screenshot does not remove the need to identify the object and the particular view.
Use an annotation layer where your tool supports one, or name the working file clearly. Mark additions as yours in the caption. Avoid drawing over the feature you want another reader to assess; a label beside it can preserve more evidence than a thick circle across it.
Show the observation before the interpretation
For an exercise, point to a short mark and write “mark beside the second line,” then place your possible explanation separately. If the interpretation changes, the location note can remain useful.
When sharing, include an unannotated view or an accessible route back to it. A colleague should be able to disagree with your reading without first reconstructing which pixels belonged to the manuscript photograph.
Keep uncertain letters and speculative links out of a caption that sounds like catalogue description. Your working notes are valuable precisely because they show an argument in progress. Labelling that layer makes the image easier to discuss and prevents a later reader from mistaking your evidence guide for part of the historical object.
Editorial illustration from the site’s image collection.