This makes it possible to see a pattern that had been invisible. This means that if a grey region consists of a grid of very small dark dots the filtering will produce a lighter grey, while a region of larger dots will be affected differently ("big-dot-little-dot"). In addition, human vision is sensitive to luminance contrast ratio. Features smaller than the resolution will also not be reproduced. We have tested Cross/Hatched colored safety paper and it complies with image ready standards. We also verify that our check backgrounds will drop out when scanned by the banks imaging equipment. It will also not be perfectly aligned with the directions of the document, causing aliasing. We have also created a Check21 compliant version of our Void pantograph. A scanner or photocopier will act as a low-pass filter on the original image, blurring edges slightly. Void pantographs work by exploiting the limitations and features of copying equipment. Typically they spell out "void", "copy", "invalid" or some other indicator message. Void Pantograph: A pantograph screen that has the word VOID hidden in it, created by using special screens and background designs.
11 FREE Security Features n Quantities start at 250 n Black imprint and numbering n 1-part only, white vouchers n Thermochromic ink n Single and Double envelopes available n Polywrap protected n n 14 Standard Check Colors. This document is printed on security paper with toner adhesion and chemical sensitivity with a void pantograph. A void pantograph option is also available in either dark blue or green ink. Normally these are invisible to the eye, but become obvious when the document is photocopied. English term or phrase: Void pantograph Sistema de segurana num documento. In security printing, void pantograph refers to a method of making copy-evident and tamper-resistant patterns in the background of a document.