It’s the wrong color blue, but in old school paste up in backshop prior to shooting for press, copy Ed’s would use BLUE pencil for last minute markup / edits because they would not show up in the final photo processing
https://en.m.wikipedia.org/wiki/Blue_pencil_(editing)
Example of pencil. https://www.jetpens.com/Caran-d-Ache-Sketcher-Non-Photo-Blue-Pencil-Pack-of-2/pd/15882
It’s the wrong color blue, but in old school paste up in backshop prior to shooting for press, copy Ed’s would use BLUE pencil for last minute markup / edits because they would not show up in the final processing
https://en.m.wikipedia.org/wiki/Blue_pencil_(editing)
Example of pencil. https://www.jetpens.com/Caran-d-Ache-Sketcher-Non-Photo-Blue-Pencil-Pack-of-2/pd/15882
It’s the wrong color blue, but in old school paste up in backshp prior to shooting for press, copy Ed’s would use BLUE pencil for last minute markup / edits because they would not show up in the final processing