Study on the Method Used to Display Self-fading Lines and Erasable Lines

Area of Science:

• Forensic Science
• Document Examination
• Material Science

Background:

• Erasable and self-fading pens are increasingly popular in China.
• Their inks disappear with heat or friction, posing challenges for document examination.
• Recovering such faded writing is crucial for forensic investigations.

Purpose of the Study:

• To investigate methods for revealing disappeared writing from self-fading and erasable pens.
• To determine the effectiveness of various techniques under different conditions.
• To establish optimal operating parameters for successful ink recovery.

Main Methods:

• Prepared ink line samples using five self-fading pens, 18 erasable pens, and three paper types.
• Examined the effects of temperature, humidity, and lighting on ink fading.
• Tested luminescence, UV, sidelight, electrostatic indentation, low-temperature, and solution-based revealing methods.

Main Results:

• Multiple methods, including luminescence, UV, sidelight, electrostatic indentation, low-temperature, and solution techniques, proved effective.
• Optimal operating conditions for each revealing method were identified through experimentation.
• The study provides a systematic approach to recovering intentionally obscured text.

Conclusions:

• Disappeared writing from popular Chinese pens can be effectively revealed using scientific methods.
• The findings offer valuable techniques for document examiners to recover critical evidence.
• Further research could explore the long-term stability and chemical properties of these inks.