Determine the X and Y coordinate of the start of the bar code, and because the location of the bar code may vary slightly from document to document, you must also measure the approximate difference from this point that the bar code may be printed, called Delta X and Delta Y.
The start of the bar code is noted on the sample bar code above. All measurements reference this point.
X measures the distance from the left edge of the page to the start of the bar code.
Y measures the distance from the top edge of the page to the start of the bar code.