The pen your respondents use has a direct impact on scanning quality and recognition accuracy. We recommend using a black or blue ballpoint pen for the best results.

Why pen works well

Pen creates dark, consistent marks that scanners can easily detect:

• High contrast. Black or blue ink stands out clearly against white paper.
• Consistent darkness. No variation from pressure differences.
• No smudging. Ink does not smear during handling.
• Good longevity. Marks remain clear over time and through storage.

Recommended pen types

• Ballpoint pens produce the most consistent marks
• Gel pens work well but may smear if not given time to dry
• Felt-tip pens are acceptable but avoid thick markers that may bleed through paper

Colors to use

Black and blue ink produce the best results. Avoid light colors such as yellow or light green, as they may not be detected reliably at lower scan resolutions.

Marking guidelines

• Fill boxes completely rather than using light checkmarks
• Apply firm, consistent pressure
• Make marks dark and solid
• If correcting an answer, cross out the incorrect mark clearly

If respondents must use pencil

We recommend pen whenever possible. If pencil is unavoidable, instruct participants to fill in the entire bubble or checkbox area with solid, dark marks. Thin lines, light checkmarks, or partial marks may not be visible to the scanner and can lead to missed responses.