I heard that when you make a color copy to deter counterfeiting(sp?) the copies comes out with a code that is embedded in the copy that makes that copy traceable back to the machine using the serial number or something like that.
Is this true?
Been watching America’s Most Wanted? 
Here’s a page that supports the claim.
Of course, I don’t know if that guy has any credibility; it’s just the first thing that showed up on Google.
From friedo’s link:
I don’t know what it ultimately says about the credibility of the report that article linked, but I worked for a small company that had a color copier in 1980. 3M claims they had one out in 1968.
From the linked site:
Always a warning sign - when someone claims “the law requires” and doesn’t mention what law.
- Rick
[fixed coding]
[Edited by bibliophage on 12-01-2001 at 10:23 PM]
Store name, store location, and time are going to be variable information. Copiers can be purchased, sold, and rented. Updating them all would require virtually ever copier repairman to be in on the plan, which means that detailed information would likely have been leaked within days of the protocol being implemented. Additionally, given the legions of clever people that dedicate vast amounts of time to figuring just this sort of tricky thing out, the fact that we haven’t heard specifics begins to weigh.
Second, consider what form this invisible mark would take. What, pray tell, is the resolution of most color copiers? Not high enough, I think, to store much information in a soi-disant ‘invisible code.’ Steganography in printed images is very difficult, and I would wager that it is far too difficult for such broad application as ‘every major color copier.’ When you throw in the number of high-quality color laser and ink jet printers that can be purchased anonymously for cash at your local Mega-Mart, this becomes downright ridiculous- not to say that puts it past a paranoid spook.
Take a piece of colored paper, photocopy it and see if there are any irregular marks. That should answer your question.
How does this prevent someone at home using their color printer from making bills? That would seem far more dangerous than trying to use the color copier at Kinko’s in front of everyone to counterfeit.
The fact of the matter is that unless you have the right kind of paper, counterfeiting US currency is next to impossible and really obvious. And it is impossible to get the paper, and if you try to buy something similar, you get a nice visit from the Secret Service.
I read somewhere - a book called “indelible evidence” if I remember correctly- that laser printers and copiers which use a drum covered in toner to produce an image leave their own unique “fingerprint” on every copy. This is because, I believe, the drum and optical components of the copier usually contain irregularities, which show as a pattern of tiny “speckles” on the finished copy.
This becomes more obvious as the printer / copier gets older and the drum / lenses get dirtier, and if you print a copy of “nothing”, you may well see a repeating pattern of faint speckles.
This technique was used to identify a blackmailer in the late 1980s, so if your intentions are of this nature, use an inkjet printer (someone else’s).