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
- Cross checkboxes with a clear X or fill them in completely
- Avoid light checkmarks, as a checkmark can easily drift across multiple answers or land outside the box
- Apply firm, consistent pressure
- Make marks dark and solid
Correcting answers
By default, any mark in a checkbox (a check, a cross, or a completely filled box) counts as a response. If your respondents may need to correct mistakes, switch the Recognition mode to "Check, Cross to respond, fill-in to unmark" in your survey's settings. With that mode enabled, respondents cancel a mark by completely filling in the box, and the printed footer instructions on the survey update to explain this.
Avoiding faint marks
Always provide or recommend pens to your respondents. Thin lines, light checkmarks, or partial marks may not be visible to the scanner and can lead to missed responses.