I designed a pen holder based on a Roman column and printed my LOGO on the bottom. I have uploaded the source file and can modify it to the size you need.
This is an S size
size:
Height: 90mm
Width: 80mm
The PLA printing I used set the bottom surface to 5 layers and the fill to 10%. The other parameters are the default parameters of Bambu Lab.
I also designed an L-sized one to provide different usage scenarios. You can visit my homepage to view it.