I bought a set of four small flip-top Dinky Dips set in a wooden holder last summer. I LOVE Dinky Dips! I thin gouache with water until it flows through a dip pen and these small Dinky Dips are the perfect size to do this while minimizing the amount of paint needed, and covering them means it doesn't evaporate away - just stir and use again!
The caps, however, are not so good. Two of the four caps have split so far - one of them either arrived split or split soon after arrival - and while one of the split caps still covers well enough to stop drying out, I assume it's only a matter of time before it splits across the top.
Next time I'm trying the screw-top ones.