I designed this clip for the samla container from ikea in with i store my filament. It really sturdy and helps keeping the container sealed.
It shouldn't be in the way when stacking multiple boxes.
I add printprofiles for a single 40 mm long variant to test if you like and also 4 x 40mm and 4 x 60 mm long also the stls for them are there so you can print as many as you need.