noun
An oil-based marker that writes on many surfaces and is water-resistant. Often contrasted with 水性マーカー (water-based marker).
油性マーカーで段ボールに宛先を書いた。
I wrote the address on the cardboard box with a permanent marker.
ホワイトボードに油性マーカーを使うと消えなくなるので注意。
Be careful: if you use a permanent marker on a whiteboard, it won't come off.