I think there must be some kind of fuss in my house that takes my pens to an alternate universe. At least that's the explanation I found for her constant disappearance. So I decided to buy a large number of cheap pens so as not to miss when they disappear one by one. They tick all the boxes except I'm going to miss them because while they're cheap and weigh about the same weight for their equivalent air volume, they perform like champions. Every time the first time. All I can ask is that they stay in this universe long enough for me to use them!