If you open a QR Code in EPS format in CorelDraw, you might experience the units having a thin line around them.
 Thin lines around QR Code pixels
Thin lines around QR Code pixelsJust press the CTRL-A and then the CTRL-L key to combine the units.
 Removed thin lines around QR Code pixels
Removed thin lines around QR Code pixelsNow the thin lines are gone.