If you don’t know, Christian and I (Carol) are the proud owners of a printing press. Christian bought it right before we were married, so I guess, in a way, it counts as a wedding gift. . .? Anyway, when you have a printing press, you need to also have type (the little letters in which you can print). When you have type, you need a place to put it. So you have a type case.
When you have no room for type cases (or printing presses for that matter), the cases can be used as a way to store/display thread.
It is much easier to see all the colors we have available to use when we display them like this.