MIC / Yellow Tracking Dots
Definition
Machine Identification Code: faint yellow micro-dots printed by many colour laser printers and copiers on every page, encoding serial number and timestamp. Used for source-machine identification.
- Full name
- Machine Identification Code
- Appearance
- Faint yellow micro-dots
- Printed by
- Many colour laser printers/copiers
- Encodes
- Serial number and timestamp
- Use
- Source-machine identification
Common questions
Why are the dots yellow and hard to see with the naked eye?+
Yellow ink has low contrast against white paper under normal lighting and reflects poorly to the human eye, so manufacturers chose it to keep the code functionally invisible during ordinary reading while still being recoverable under magnification or specific lighting such as blue light or UV.
Does the absence of visible tracking dots mean a document was not printed on a colour laser device?+
Not necessarily. Not every colour laser printer or copier model implements the code, and even models that do can vary in dot pattern, so absence of visible dots is not conclusive proof the device lacks the feature without examining the specific model's known behaviour.
Related terms
- ESDA
- Electrostatic Detection Apparatus; detects latent indentations in paper by charging the surface and cascading toner particles, revealing tracing stylus pressure and writing...
- Inkjet Printing
- Non-impact printing that sprays liquid ink droplets onto paper. Two main technologies: thermal (HP, Canon, bubble-jet) and piezoelectric (Epson).
- IR Luminescence
- Emission of near-infrared radiation by ink dye molecules when excited by visible light; different ink formulations luminesce at different intensities, allowing differentiation...
- Oblique-Light Photography
- Photography of a document surface using illumination at a low angle (10 to 15 degrees from the paper plane), which casts shadows...
- Photographic Reproduction
- Lab-side imaging of a questioned document using controlled lighting (oblique, transmitted, coaxial), filters and wavelengths from UV through visible to IR, to...
- Transmitted-Light Photography
- Light passed through the paper from behind to reveal watermarks, paper-fibre disturbance, security threads, erasures and chemical thinning.
- VSC-8000
- Video Spectral Comparator by Foster + Freeman, the standard QD instrument in CFSL and GEQD labs, with broadband visible, UV (254, 365...
- Xerography
- Dry electrophotographic process invented by Chester Carlson (1938). Photoconductive drum is charged, exposed to image, dusted with toner, transferred to paper and...