Identifying original drawing vs. copies 2

[kjoiner]

Hello,

For years, we used a stamp that said "ORIGINAL IF RED" to identify the original drawing released by engineering. It was easy to identify a copy because the red ink would be black on a copy. With the advent of color copiers, it will now be more difficult to determine what is original. Ideally, copies would be labeled or stamped "COPY" or similar but we do not have a dedicated document control person.

Stamping the drawing, however, still does provide some feedback. When I check and approve a drawing, I still use the "ORIGINAL IF RED" stamp. That does show that I have reviewed the drawing.

My question is whether I should continue stamping the drawings or develop some better method of identifying copies of drawings.


Thanks,
Kyle

 

[berkshire]

Drawoh,
We used to have " Transparentizer fluid " soak a copy in that and you could make a blueprint off it.
B.E.

You are judged not by what you know, but by what you can do.

 

[3DDave]

As an experiment I made a pen plot with transparent orange ink. The image was so faint I had a difficult time reading it. However it made the darkest blueprints, much more contrast than black ink or plastic lead. We were pretty far past graphite then, so I'm not sure.

In any case a blueprint of a blueprint, even with a transparent background, would probably be low contrast as the UV from the lamp would not be much impeded by the blue. Perhaps there is a chemical treatment that would couple with the blue.

To the original question - there are some possibilities.

1) Did you know that dollar bills have anti-copy/anti-scan/anti-edit features built in? While it is possible to use completely analog methods, any digital work-flow is likely to be stopped by it. You can see it as a pattern of yellow dots in the background of most currency. It seems this technique was developed by Digimarc.

Something similar seems to be available in pre-printed form

http://www.protectedpaper.com/product_p/obxuc.htm

The following pattern is used on currency, though the article suggests that US currency also uses some other scheme.

https://en.wikipedia.org/wiki/EURion_constellation.

It's hard to say it will work from images generated on color laser printers - it may be the resolution is too low or the yellow dot pattern the copiers already applied by the laser printers will interfere.

http://www.instructables.com/id/Yellow-Dots-of-Mystery-Is-Your-Printer-Spying-on-/

Interesting and frightening, Digimarc licensed the marketing of unspecified patents to Intellectual Ventures, an IP/Patent Troll house founded by former Microsofties Nathan Myhrvold and Edward Jung.

https://en.wikipedia.org/wiki/Intellectual_Ventures#Controversy

However, at least this patent by Digimarc (there are many others) is lapsed due to non-payment of fees.

https://www.google.com/patents/US64...ved=0ahUKEwiMyPiXveTRAhUr7YMKHWdaALQQ6AEIHDAA

2) Another approach is to use color paper for the distributed copies. Even good color copiers will have trouble duplicating the shade and they will be identifiable among paper stacks.

3) A third approach is to use stamps, such as are used for legal papers by a Notary Public. It will be a while before 3D printers are making paper documents.

 

[berkshire]

3D Dave,
This is interesting. Some of the German aircraft companies I used to do work for, would sent their drawings printed on Orange paper, which were just about impossible to duplicate.
B.E.

You are judged not by what you know, but by what you can do.