If space is of your concern you might want to consider to hang your pens instead of wasting desk space. I use wood beams (44mm x 24mm x 2000mm) between a wall and a shelve to store boxes of stuff (e.g. filament). To make use of the space under the boxes I created these hanging bunch. Print two and place them next to each other.
Variations & Remixes
You might want to hang more pens under each other or need a different diameter. Just download the FreeCAD file and open it with FreeCAD (free and open). Open the spreadsheet ‘sizes’ change the values for your diameter and/or number of rows and export the new file for printing.
Feel free to change the mounting mechanism for your needs and upload a remix. However I can't help you with that.
The author hasn't provided the model origin yet.