technology is awesome!

[illusion88]

I recently finished an online traffic school program. I just recieved the certificate of completion in the mail. When I went to copy it I noticed that the copy had these giant letters saying "UNOFFICAL COPY" and "Not an official Document". That is so cool! Any idea on how they do that? What reacts with the heat to do that while not showing up on the original?

Either way I am impressed.

 

[Ogg]

I think that existed even when Roger was in high school man

 

[minendo]

Some photo papers have this same feature. The place that did my sister's senior pictures had it.

 

[illusion88]

Originally posted by: Ogg
I think that existed even when Roger was in high school man

Well, its the little things in life that are worth the most.

cheers hun! :beer:

 

[MattCo]

It is not the heat that causes it. It is the background watermark printed onto the paper. It has small pixels that spell that out in the background, but when the light from the copier lights it up, the resolution of the machine cant distinguish the individual pixels and it shows up on the paper. Maybe that sentence didn't make sense, but it sounds good when the little voice in my head said it.

-MC

 

[Amorphus]

Originally posted by: MattCo
It is not the heat that causes it. It is the background watermark printed onto the paper. It has small pixels that spell that out in the background, but when the light from the copier lights it up, the resolution of the machine cant distinguish the individual pixels and it shows up on the paper. Maybe that sentence didn't make sense, but it sounds good when the little voice in my head said it.

-MC

so it's a very diffused image?

 

[Pepsi90919]

Originally posted by: MattCo
It is not the heat that causes it. It is the background watermark printed onto the paper. It has small pixels that spell that out in the background, but when the light from the copier lights it up, the resolution of the machine cant distinguish the individual pixels and it shows up on the paper. Maybe that sentence didn't make sense, but it sounds good when the little voice in my head said it.

-MC

small pixels?

 

[illusion88]

Upon close inspection of the original paper I noticed that there are small black dots that make out the letters. Those are the small pixels that he is refering to. They are hard to see at a difference but apparent (under a bight light) when you look at it closely. I think it works because the light hits it and registers those black dots as darker then then the surrounding image so it prints those darker then the background.

 

[Nohr]

Same as the watermark in the new $20 bills? Can you see it on the original when you put it up to a bright light?

 

I think that existed even when Roger was in high school man

You die now.


Ogg

Please enlighten me as to what your original nick was before you got banned and resigned up under this nick.

 

[CraigRT]

That is kinda cool.. I did mine the old fashioned ghetto way 🙁

lol!