Your laser printer is not perfect. If you print a big 8“ x 10” rectangle and measure it on the paper, it will not exactly be 8×10. Most of the time it doesn't matter. But if you are printing a drilling guide for mounting holes, or if you are printing a pcb layout that have long footprint (like a slider), then your part won't fit.

Well, we won't actually modify the printer. All we are going to do is measure the “error” and compensate in your design software before printing. If your printer has a tendency to print objects on the X axis longer, we will shorten them in the software, so they have the good size once printed.

- Print this document, 100%, US letter size http://s000.tinyupload.com/index.php?file_id=02292925287500759531

- For each side of the rectangle, measure the side and fill up the first number, then do the math and write it down

- In your software, select what you want to print, and change the percentage (transform) accordingly to X and Y.