Replies

I remember that 30 years ago, my Office Manager would not buy blue highlighters because if you used a blue marker, whatever you highlighted would not show up on a copy. Don’t know if new technology has changed that.
_______________________________
That’s an observation I haven’t thought of for many years, but now it comes back to me that the only pen to use for signing documents, which subsequently required copying was the black ink pen. I don’t know the technology in DEWs, but it may operate with lasers and there may be something unique about the light spectrum and the color blue.

...it comes back to me that the only pen to use for signing documents, which subsequently required copying was the black ink pen.

I saw where blue pen was used for original signatures. Any document with a black ink signature was a known copy. Many companies and agencies switched to black ink signatures to treat originals and copies as the same. The switch wasn't about copier and scanner technology, it was about audits. The inspectors would no longer raise a flag if they didn't find blue ink originals in the master files.