1. Oil-Based Marker Lines Act Differently on Notebook Paper and Glass
If you write your name on the corner of a notebook with an oil-based marker, it is hard to remove, even if you try to rub it out. However, if you draw a line on a plastic container or a piece of glass, rubbing or wiping it can make the line fade or disappear. [1]
It is the same pen, but the result changes depending on the surface you write on. The clues to this difference seem to lie in the contents of the ink and the surface texture of the material. First, let us look at what is inside the ink.
2. Why Oil-Based Ink Does Not Wash Away with Water
If you spill water on writing made with a water-based pen, the color spreads and runs. Water-based ink is made by dissolving dye in a liquid that contains water and wetting agents. Most of these pens are not water-resistant and wash away easily. [1]
In contrast, oil-based dye ink is a fast-drying ink where dye and resin are dissolved in organic solvents, such as alcohol-based liquids. [1] Once the solvent dries and evaporates, the color and resin that remain are difficult to dissolve in water. [1]
3. Why Oil-Based Ink Is Hard to Remove from Paper
Under a magnifying glass, paper looks like tiny strands with small gaps between them. A lifestyle information site explains that oil-based ink is made of oil, dye, and resin. The oil carries the dye into the gaps in the material, and as the resin dries, it increases the adhesion to the paper. [2]
Another childcare information site notes that the longer the ink stays on the material, the more it soaks in, making it harder to remove. [3] This explains why paper, with its porous structure, holds onto the ink so tightly.
4. How Smooth Surfaces Like Glass and Plastic Change the Result
Glass and smooth plastic have fewer gaps than paper, so the ink has difficulty entering the interior of the material. Therefore, it is thought that the ink simply sits on the surface. [3]
Guides on how to remove marks suggest rubbing plastic and glass with an eraser. For stubborn stains, they recommend wiping with a cloth soaked in disinfecting ethanol or nail polish remover. On the other hand, cloth, wood, leather, and paper are described as difficult to clean. [3]
Safety Note: Using solvents like ethanol or nail polish remover can change the color of or damage the material. You must be careful with ventilation and fire sources. If you try this, do so with an adult, starting in an inconspicuous spot. [3]
5. How Whiteboard Markers Make Oil-Based Ink Easy to Erase
According to a document from Teranishi Chemical Industry, whiteboard markers are a type of oil-based ink. They add a "release agent" to the organic solvent, pigment, and resin to allow the written lines to be wiped off. The difference from ordinary oil-based markers is whether or not they contain materials designed to peel the ink away. [1]
The "Macky that erases with water" is introduced as having a mechanism where a water-soluble glue mixed into the ink dissolves when wiped with water, causing the color material to peel off. [4] It can be erased on smooth surfaces like plastic, glass, and metal, but it cannot be erased with water on paper or cloth where the ink soaks in. [4]
This product was introduced at an exhibition in July 2014 and won the Excellence Award at the 23rd Japan Stationery Grand Prix. It is said that you can write on glossy paper, and the ink will not come off when touched by hand. [5]
In a high school research project, students tested writing on paper with whiteboard markers. They found that the ink erased on "stone paper" with a glossy, smooth finish, but did not erase on straw paper or copy paper. This is just one example of a student experiment, limited to the result that it erased on glossy stone paper. [6]
6. What Ink Colors Are Made Of: Dyes and Pigments
The history of marking pens in Japan begins in 1953, when Teranishi Chemical Industry and Uchida Yoko jointly developed and sold the fast-drying oil-based marking pen "Magic Ink." [1]
Oil-based ink color materials include pigments in addition to dyes. Oil-based pigment ink is an opaque, fast-drying ink that uses pigment instead of dye. It does not dissolve in water, has excellent light resistance, and is suitable for plastic, metal, glass, ceramics, and outdoor signs. Some colors, like white, gold, and silver, cannot be made with dyes. [1]
For example, Sakura Color Products' oil-based marker "Paint Marker Pro" is pigment-based. It can write on metal, glass, plastic, rubber, stone, and wood, and is introduced as having high water and light resistance. Fluorescent colors, however, are dyes. [7] Zebra's Hi-Macky can also write on paper, cloth, wood, cardboard, glass, plastic, metal, and vinyl, but soft vinyl products are not suitable. It is not a pen that can write on "everything." [8]
7. A Home Experiment: Comparing Oil-Based and Water-Based Pens on Plastic
If you want to investigate further, you can try this at home. Take a plastic lid from a disposable container. Draw lines on it with an oil-based pen and a water-based pen. Then, rub them in order with a wet finger, a dry cloth, and an eraser to compare how they come off. Compare this with lines drawn on paper. Ask an adult to help. Cover the table with newspaper, and wear clothes that can get stained.
When you go out, visit a stationery store. Look at the back of oil-based pens or whiteboard markers, or read the descriptions. Compare how they list the "materials you can write on." Manufacturer product pages and documents explaining types of writing instruments are good references.