Use only printers that produce neat, readable text with no stray marks or smudges.
smudges the boundaries, and leaves them in confusion.
Take care not to leave smudges on the answer sheet.
Distant and faint gamma-ray burst afterglows will appear as tiny smudges of light even to the powerful UVOT.
Dark mascara gives definition, but avoid harsh eyeliners or thick mascara - blobs and smudges will be magnified too!