We recommend using pen for best recognition results. While both pen and pencil work, pen provides superior accuracy and fewer scanning issues.

Why pen works better

Pen creates darker, more consistent marks that scanners can easily detect:

• Higher contrast - Black or blue ink stands out clearly
• Consistent darkness - No variation from pencil pressure
• No smudging - Ink doesn't smear like graphite
• Better longevity - Marks remain clear over time

Using pencil effectively

If you must use pencil, follow these guidelines for best results:

Choose the right pencil

• Use #2 or HB pencils (standard darkness)
• Avoid hard pencils (H, 2H) that make light marks
• Ensure pencils are well-sharpened but not too sharp

Marking techniques for pencil

• Fill boxes completely rather than using checkmarks
• Apply firm, consistent pressure
• Make marks dark and solid
• Avoid light sketching or partial marks

Common issues with pencil

Light marks

Faint pencil marks may not scan properly, especially on:

• Lower quality scanners
• High-speed document feeders
• Photocopied surveys

Erasure problems

• Incomplete erasures leave ghost marks
• Eraser residue can obscure responses
• Multiple erasures damage paper

Best practices for your study

Standardize writing instruments

• Provide pens at survey stations
• Specify pen use in instructions
• Keep backup pens available
• Use the same color (black or blue)

Sample instruction text

"Please complete this survey using a black or blue pen. If you need to make corrections, cross out the incorrect answer and clearly mark your new choice."

Scanner settings for pencil

If using pencil is unavoidable:

1. Increase scanner darkness/contrast settings
2. Use higher resolution (300 DPI minimum)
3. Clean scanner glass frequently
4. Consider scanning in grayscale rather than black/white

Quick comparison

Feature	Pen	Pencil
Recognition accuracy	Excellent	Good (if dark)
Scanning reliability	Very high	Variable
Correction method	Cross out	Eraser (problematic)
Long-term storage	Permanent	May fade
Cost	Higher	Lower

Recommendations by survey type

High-volume surveys

Use pen exclusively to minimize processing errors

Field surveys

Provide pens but accept pencil as backup

Educational testing

Follow your institution's standards

International studies

Consider local preferences but encourage pen use

By choosing pen over pencil, you'll reduce verification time and improve data quality. The small additional cost is offset by fewer processing errors and faster results.