I had a lot of trouble getting the original design to close because the hinges wouldn't line up. So, I remixed the model to use 2 M2.5 x 30mm screws for the hinges. I tried printing in a nice silk PLA, but the hinges kept breaking. I recommend regular PLA at a minimum. 

You may need to sand down the hinge slightly if the layer lines interfere with the case closing. 

5/9/2026 - I have verified that this will fit the 0.25mg/0.5mg and 1mg pens. If you know of other pens that will fit please post in the comments!