By Andy Pasquesi Updated Mar 24, 2022
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Every permanent marker is a sealed plastic tube that holds a porous, sponge‑like core saturated with ink. The tip, a small protrusion of the core, draws ink from inside the tube via a siphoning action. The ink itself is a blend of three components: a colorant, a solvent, and a resin.
The colorant—whether a pigment or a dye—creates the visible hue. Dyes dissolve in water, while pigments are generally water‑insoluble and resist humidity. Because of their stability, pigments are the preferred choice for most markers, ensuring that lines remain sharp even after prolonged exposure.
The solvent is the lifeblood of the ink. It carries the colorant and resin through the sponge and, once the marker is used, evaporates from the paper, leaving the permanent components behind. Early manufacturers used xylene, but by the 1990s they switched to less toxic alcohols such as ethanol and isopropanol, especially as children began using markers in school settings.
The resin acts like a glue, bonding the colorant to the substrate once the solvent has disappeared. A resin that remains sticky inside the sealed tube allows the ink to stay fluid, while its adhesion to paper prevents the pigment from flaking off after drying.
The most significant distinction lies in the resin’s polarity. Permanent inks contain non‑polar resins that do not dissolve in water, making stains difficult to remove with a standard wash. Dry cleaning solvents, however, can dissolve these resins and lift the mark. Non‑permanent inks, in contrast, use water‑soluble resins, allowing them to be washed away. Additionally, permanent markers often employ pigments or dyes that resist water, further enhancing their longevity.
