If ink is not completely dry, the color of it may fall. Not available to use it on blackboard for chalk. The color of it may fall by strong rubbing and rainy momentum. It may be hard to erase it depending on type of blackboard.
Dimension (Shaft Diameter Φ × Thickness × Full Length) (mm)
Line Width (mm)
* Products that meet your criteria are shown in
A certain company's product has good coloring although it is often good to color to the board, but there is a big disadvantage that it will come off as time passes. Since there is not such a thing here, we recommend this if you stress importance to durability even if the color development is bad.