Back-side of the model green and purple stands with red supports are single-wide and used for the ends. Yellow, blue and orange for double-wide sections between modules. 

Each shelf unit can house 5 bottles, 30 bottles for a module. Recommended build order: Build the stands first then glue in the bottom shelf of a module, then the top shelf, then fill in the other shelves before moving on to the next module. 

Don't mind the goop at the support - I “welded” some PLA in there as a test intead of using screws and it worked fine. I also anchored the entire stand to a slab of wood so it is more stable. 

Lots of modules, means lots of room for paint. 

There are some drawer files that can be used under the first shelf on the bottom. If you have the space in-front of the stand, these are good storage spaces for small files, knifes, and various small tools or supplies.