If you open the case to use the stamp at a bank or government office, have you ever had a stamp fall out of the case?
When you open the stamp case, it's hard to tell which is the upper.
In fact, the notch on the handle will be the mark in such a case.
As you can see if you zoom in and look at it, only the upper part of the handle has notch. If you open the stamp case with this notch facing up, you can always open the stamp so that the stamp does not fall out. If you drop a registered seal or a bank seal and the stamp surface is chipped, it may become unusable, which can be troublesome. When opening the lid, let's open the stamp case with the notch facing up!