I've designed a modular storage system for my paints. It can be used for 10ml, 17ml and 23 ml bottles. I has 3 different hights of bases and 3 types of holders. All can be connected with a snap in system. There are also raisers in case a base needs to be stretched up. 

You can stack as many bases up as you need. on the top there is can be mounted a holder with a handle to easily manipulate the whole thing.

I’ve printed the bases in PLA. The holders need to be printed in PET-G as they need to be quite elastic.