I taked to NCEES they said " Many thousands of people have used the pencils we have gotten from the same company for many years without trouble. Any form of erasing can cause smudges, and for the most part, the pencils we use work perfectly fine. Although it brings a very important point about why we require that everyone use the same pencil/eraser.As for the exam itself, erasures rarely make it difficult for the digital computer system to score. We spot check many answer sheets and even with large smudges on the paper, the computer is able to pick out the answer you selected. We have actually NEVER found a mistake by the computer scoring." This is perfect response to Ken 3.0's response of " No, but eraser marks count as double against you.", basically we should be good.