Markers

According to the manufacturer, Sharpie permanent markers are designed to write practically everywhere, however the ink does not tend to stick or last long on non-porous surfaces, like ceramics.

Non-porous surfaces are those which do not allow liquid or air to pass through them. These surfaces also include glass, plastics, metals, and varnished woods.

A "cleanroom" is a controlled environment area (CEA) typically used for manufacturing items that require a low level of environmental pollutants.

Airborne particles are also controlled within a cleanroom!

Sharpie products, such as the Ultra Fine Tip Retractable Permanent Marker, are produced in a cleanroom, making their products cleanroom certified!

Following these steps can help restore your Fineliner Pen:

Pour about one cup of warm water into a bowl.

Put the marker(s) tip-down in the water. 

Let the markers dry on a rag.  

Replace the caps when done.  

Alternatively, use a few drops of vinegar.  

Consider injecting water into the marker.

This caddy kit can be easily mounted to any surface using magnets or double-sided tape!

You can find the Safety Data Sheets for all colors here. MSDS