I have seen a lot of stackable containers, but I wanted some that stacked and stayed together to make for easier and more convenient storage. I also set myself a challenge to try and develop some that didn't require any supports as no supports saves filament, time, and has overall better quality. I stayed with traditional threading for the lids on the containers themselves but used a twist lock mechanism for the couplers.

These containers make it very easy to put small every day items (or snacks) into and throw them all into a backpack, purse, bag, what have you, while conveniently keeping the containers together. If you so wish to only print the containers themselves, the twist lock latches on the containers are minimal and still make for easy and convenient storage.

These are a current work in progress and I plan to continue to improve on them. Let me know what you guys think and if you have any design improvement recommendations. 

Use caution when scaling as it degrades the quality of the threads.