Why does coloring over permanent marker with dry erase remove the “permanent” markings?

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Why does coloring over permanent marker with dry erase remove the “permanent” markings?

In: Chemistry

“Permanent” ink is carried by a solvent which rapidly evaporates. Coloring over permanent marker with dry erase briefly exposes the permanent ink to solvent and allows it (the ink) to be wiped away quickly.

Marker ink was two components: the dye or colourant, and a volatile solvent that exists to carry the dye as a liquid for writing. The solvent evaporates relatively quickly leaving behind the dye as markings.

Dry-erase markers have dyes that do not bond well to glossy surfaces, so can easily be removed with a cloth.

Permanent markers have a dye that usually is not water-soluble, so is relatively long-lasting.

However, the solvent in dry-erase markers is often quite good at dissolving the dye in permanent markers, so writing over permanent marker with a dry-erase one helps lift the dye from the permanent marker.