My hubby really likes this marker, Artline 70 High Performance Marker from Shachihata. The tip of the marker is fiber, and not too big tip. The marker is waterproof and permanent, so he usually uses it like on top of the cardboard. He also uses it for pipes because his work involves piping and machinery and stuffs. He works in a factory and this marker is very effective in aiding him in the workplace. And what's more, is that once the marker is used, the mark it results is instant drying. And I think the durability is longer than his previous marker brand. I assume one marker is for about 3-4 months depending on the frequency of use. I notice he always carries this whenever he goes to work. He always buys this like five or more at a single purchase, because you know why? Because he often loses his marker. Well he likes to put this marker around, making our place messy, and when he wants to use it, he's just like, asking me all the time where the marker is. So I suggest him, to buy many of it at once. I think maybe he loves this marker very much and won't go to work without it.