Halo
Carefully created images can be hidden in the background or in a picture on a document. These images cannot be seen without the help of an inexpensive lens of a specific line screening. When placed over the location of the image and rotated the image becomes visible. If the document is photocopied the Halo image is lost.
Halo can be printed on traditional or digital presses. The advantage of traditional presses is that multiple images can be overlaid in the same location and become visible in turn as the lens is rotated.
Halo is used as a technique to authenticate the originality of the document and may be used to verify critical information within the document. For example the value of a coupon might be encoded as a Halo image that could be verified at the time of redemption or similarly the seat number on a sporting event ticket.
Read more about this topic: Security Printing
Famous quotes containing the word halo:
“Fame now wears the halo that once crowned holiness.”
—Mason Cooley (b. 1927)
“Most books belong to the house and street only, and in the fields their leaves feel very thin. They are bare and obvious, and have no halo nor haze about them. Nature lies far and fair behind them all. But this, as it proceeds from, so it addresses, what is deepest and most abiding in man. It belongs to the noontide of the day, the midsummer of the year, and after the snows have melted, and the waters evaporated in the spring, still its truth speaks freshly to our experience.”
—Henry David Thoreau (1817–1862)
“The drama critic on your paper said my chablis-tinted hair was like a soft halo over wide set, inviting eyes, and my mouth, my mouth was a lush tunnel through which golden notes came.”
—Samuel Fuller (b. 1911)