I guess the short answer is that they don't use it. While looking for some particular colors I realized that my tubes were stored here, there, and everywhere. There are probably a few more stashed somewhere I didn't come across yet. That lead me to organize and inventory them. I got these nice boxes for $.97 each. I set up a laptop on that chair to the right and sat on a milk crate and did the inventory. I have to say it feels good. Now I know what I have and where it is.