A whiteboard marker works because it uses a special type of ink that doesn't soak into the writing surface but instead sits on top, allowing it to be easily wiped away.
At its core, a dry erase marker is a writing instrument that uses a special type of ink. Unlike traditional markers, which use a liquid ink that soaks into the writing surface, dry erase markers use a much thicker, more viscous ink that sits on top of the surface. This unique property is key to their functionality.
The Science Behind Dry Erasing
The secret lies in the composition of the ink and the surface of the whiteboard.
- Special Ink Formula: Whiteboard ink contains pigments for color, a solvent to keep the ink liquid inside the marker, and a release agent (often an oily silicone polymer).
- Viscous Consistency: As the reference notes, the ink is significantly more viscous than standard marker ink. This thickness, combined with the release agent, prevents the pigments from bonding strongly or soaking into the non-porous surface of a whiteboard.
- Sits on Top: Instead of being absorbed, the ink essentially dries into a layer on the surface, held together by the binder component of the ink and separated from the surface by the release agent.
When you use an eraser, the dried ink particles lift easily off the smooth, non-porous whiteboard surface because they were never truly stuck or absorbed. The release agent ensures there's minimal adhesion.
Key Differences from Permanent Markers
Understanding the distinction from permanent markers highlights the whiteboard marker's unique function.
- Permanent Ink: Uses resins that bond strongly to surfaces and solvents that help the ink penetrate porous materials.
- Whiteboard Ink: Uses release agents that prevent bonding and is designed not to penetrate non-porous surfaces.
This fundamental difference in ink behavior is why one is permanent and the other is designed for easy removal.
