[mannys]

Hi all. I'll take the chance to introduce myself. My name is Manny...and well I'm new here.

I was wondering if there is a chemical out there I can put on computer paper so other people can not copy it with a scanner or a printer or anything along the lines of that.

I've been googling this. Nothing has come out regarding this.

Any thoughts?

[Yggdrasil]

If you print black text on dark red paper, people should be able to read it, but it should be somewhat difficult to copy.

[Borek]

If you can read it, it can be copied. Period. You may make it a little bit harder, but there is no 100% method. Best I have seen was printed black on black, but the print was glossy so it could be read at an angle. Still, such a thing works for unlocking codes for computer game which you have to enter once every time when the game is started (good, old times ) but it won't work for something longer and more elaborate.

Oh, and BTW - we have copied these codes just for sport, taking a picture with flash, I was editor of monthly computer game magazine at the time. Our copy was even easier to read then the original when printed. It took us two days, but it was back before digitial photography, now it can be done with digital camera and Photoshop in about 5 minutes.

Not sure if it is still a general chemistry...

[enahs]

Do you mean not copy at all, or just when it is scanned it displays one of those water-marks that says "illegal naughty copy" but you can not really see it on the original?

[Dan]

Still, such a thing works for unlocking codes for computer game which you have to enter once every time when the game is started (good, old times )

Wow, that takes me back. I remember squinting at black-on-black codes to play Zool on a 386 back in the early 90s!

[Mitch]

I would doubt it.

[Borek]

Still, such a thing works for unlocking codes for computer game which you have to enter once every time when the game is started (good, old times )

Wow, that takes me back. I remember squinting at black-on-black codes to play Zool on a 386 back in the early 90s!

About the time, but I doubt it was Zool - I mean, we did Zool review, but it was not done by me, and the codes I remember were of some game I have revieved by myself. Could be it was Alien Breed: Tower Assault? Or something from Pinball series? My memory is somewhat blurry Could be that codes card still lies somewhere here (I can see Pinball Dreams Deluxe manual on my bookshelf, I just have to turn my head slightly to the right ).

Yes!!!! Alien Breed it was and the card is still here!   

[Dan]

I neer played those. It could have been Zool 2, one of the Vikings games or a Lemmings game maybe, but I seem to remember it being Zool. I only had a couple of games before I swung towards consoles. I played some Monkey Island as well, but I don't think it was that.

Anyway, I'm with Borek on this one. If you can read the document by eye then I would have thought anyone who really wanted to copy it could find a way to do so.

[Borek]

MI (all 4) are my favorites - I have LeChuck's motive as a ringtone in my mobile

[lavoisier]

It's a shame that you need to print it.
If you could write it by hand, there are ways to make the writing invisible to visible-light scanners.
I won't list all of them, they are well known. One is fluorescent ink, that is only visible under UV light. I guess there are no inkjet cartridges filled with this sort of ink, are there?

But as it was pointed out, if someone is very determined to copy it, he will find a way around.

[constant thinker]

If you print black and white, you might be able to jerry rig a cartridge for an ink jet printer to print with fluorescent ink instead black ink which is what would normally come out.

So printing may be possible.

That is assuming normal scanners don't pick up fluorescent inks.