Specifications include, but are not limited to: Color: Light Blue or Equal each sheet 8 1.2" x 11" and paper weight should be 24lbs, "CHECK" will be printed on the bottom third of page, with two (2) perforations, one (1) at 3 2/3" from the bottom of the page, and second perforation at 7 1/3" from the bottom of the page, mandatory "VOID" PANTOGRAPH-A special background on the face of the check that when copied most color copiers or scanners, show the word VOID in large characters, at least two of the following security measures should be imbedded in the paper 1)Chemical protection-brown stains and black dye appear when chemicals are used to remove/alter the check. 2) Erasure protection attempts to erase areas of the check face are visibly obvious. 3) Watermark-an artificial watermark on the check that can only be viewed at an angle and cannot be reproduced by color copier, scanner or printer. 4) Dropout screen the background on the back of the check is so light that most photocopying attempts will fail. The "VOID" pantograph is mandatory and any two of the other four measures are needed for a total of three security measures. 1,000/BOX. Window Envelopes - White 4 1/8 X 9 1/2, #24 White Wove with inside Priva Tint (Security Tint) Regular Full Gum on Flap, Standard Window, Printed Return Address in Black Ink. 500/Box. Window Envelopes - White, 4 1/8 X 9 1/2, #24 White Wove, Regular Full Gum on Flap, Standard Window, Printed Return Address in Black Ink, 500/Box.