Smartphone Ballpoint Ink Aging Analysis

ISEF Category: Chemistry

Subcategory: Other  ·  Difficulty: Intermediate  ·  Setup: Home Setup  ·  Time: 1 to 2 Months

The Hook

A tiny ink mark can carry a time stamp. Forensic labs use that idea to help sort clues in real cases. You can test a simpler version with a phone camera and careful color analysis. Your project can ask how fast ink changes as light ages it.

What Is It?

This project studies how ballpoint pen ink changes color over time when light and air slowly break it down. Think of ink like a painted wall left in the sun. The color fades, shifts, or darkens in small ways that you may not catch by eye, but a camera can measure.

You are not trying to identify a mystery criminal case. You are building a model of ink aging. You take photos of the same ink marks over time, pull out the RGB values, which are the red, green, and blue color channels in a digital image, and look for patterns. Then you compare those patterns with public ink-database metadata, which can help you see whether brand, color, or formulation changes the aging curve.

Why This Is a Good Topic

This makes a strong science fair topic because you can measure a real signal without a university instrument. The core idea is testable with a phone, a steady light source, and careful image analysis. It also connects to forensic chemistry, document analysis, and how materials change with time, which makes the work feel real. You can learn how to control variables, build a calibration model, and compare groups with data instead of guesses.

Research Questions

• How does light exposure change the RGB values of ballpoint ink marks over time?
• What is the effect of ink brand on the rate of RGB color shift during accelerated photo-aging?
• Does ink color change more in the red, green, or blue channel after aging?
• To what extent does paper type change the apparent aging pattern of the same ink?
• Which ink brands show the largest separation in RGB values after the same aging treatment?
• How does your phone camera setting change the repeatability of ink color measurements?

Basic Materials

• Assorted ballpoint pens from different brands and colors.
• White printer paper and one or two other paper types.
• Smartphone with a working camera.
• Stable desk lamp or light box with fixed bulbs.
• Ruler or printed alignment guide.
• Tripod or phone stand.
• Computer with spreadsheet software.
• Gray card or white reference sheet for photo correction.
• Clear sleeves or folders to store samples.
• Masking tape for marking sample positions.

Advanced Materials

• Standardized paper stock from the same batch.
• Multiple ballpoint ink brands with known public metadata.
• Color reference chart for camera correction.
• Digital camera with manual exposure control.
• Spectrophotometer or colorimeter, if available, for validation.
• Environmental chamber or controlled light-aging box.
• UV-safe light source for accelerated aging design.
• Analytical balance for documenting sample preparation consistency.
• Software for image segmentation and curve fitting.
• Reference ink standards from a documented collection, if accessible.

Software & Tools

• ImageJ: Measures color channels from ink images and helps compare samples over time.
• Python: Runs data cleaning, calibration, curve fitting, and visualization for your RGB data.
• Google Sheets: Organizes sample metadata and tracks aging results in a simple table.
• PubChem: Helps you search related chemical terms and background on dye families.
• PubMed: Lets you find review articles on ink aging, forensic document analysis, and color measurement.

Experiment Steps

1. Define the ink, paper, and lighting conditions you will hold constant.
2. Choose one aging variable first, such as light exposure level or storage condition.
3. Build a photo setup that keeps framing, distance, and white balance consistent.
4. Plan a color measurement method that turns each image into comparable RGB numbers.
5. Design controls that separate true aging from paper effects, camera drift, and lighting noise.
6. Set up a data table that links each sample to brand metadata, exposure history, and measured color shift.

Common Pitfalls

• Changing the phone distance or angle between photos, which makes the same ink look different.
• Letting auto white balance stay on, which can fake a color shift that is really a camera shift.
• Comparing ink marks made on different paper textures, which can change how the color appears.
• Using mixed light sources, which adds color noise and weakens your model.
• Aging too few brands or too few replicates, which makes the pattern look stronger than it really is.

What Makes This Competitive

A stronger project goes beyond simple before-and-after photos. You can compare multiple brands, test whether paper type changes the aging curve, and use a real calibration method instead of raw phone colors. You can also try a harder analysis, like classification or regression, to see whether your model predicts ink age or brand from RGB data. That kind of careful design makes your work feel like forensic science, not just image taking.

Project Variations

• Test black, blue, and red ballpoint inks separately to see whether pigment choice changes the aging curve.
• Compare indoor light aging with dark storage to isolate the effect of photo-oxidation.
• Add a paper comparison using notebook paper, copy paper, and cardstock to test how surface texture changes measured color shift.

Learn More

• USGS Spectroscopy and imaging resources: Search the USGS site for free background on spectral measurement and material analysis.
• NIH PubMed: Search review articles on ink aging, forensic document examination, and colorimetry.
• NIST Forensic science resources: Look for measurement standards and document analysis background from NIST.
• MIT OpenCourseWare Chemistry: Use free course materials to review spectroscopy, molecular structure, and chemical change.
• Journal of Forensic Sciences: Search recent articles and reviews on ink dating and document examination through library or open-access access options.