Cards are scanned in using an Epson ES-400 II - meaning you're getting a very close and high quality image.  Cards are scanned while in a penny sleeve for protection.  If you see lines all going in one direction on the card, they are not on the card; the lines are on the penny sleeve and are a result of the scanning process.  

Die cut cards or cards thicker than a standard trading card are not scanned and individual photos are taken - hence the different background on some cards.