Stackable Pen Holder Desk Organizer

A simple modular pen or marker holder for your desk or workspace. 

I designed this for my Winsor & Newton Promarker brush marker set, but can easily fit any normal pen or markers as shown in the images. If unsure if your pens will fit, the dimensions of the holes are: 16.8 x 16.8mm (H x W), with a diagonal dimension of 20.1mm. Depth of the holes are 117mm. 

The top recess is 125 x 81mm and 2.8mm deep (measured at top edge). It is designed to help locate any additional modules added on top, or as a dish to hold highlighters, erasers, etc. 

The design allows for the white outer shells to be glued together, or alternatively they will snap and hold without any glue. 

There are two alternative shells for the extension module, both are compatible with the base module. However, if the extension module is used on it's own, the rounded shell version will sit lower than the pointed version. 

Any constructive feedback is always welcome.