Vessel linework

[Jorge_Stolfi]

It's probably just a simple way to create a container, a cylinder is possibly the most obvious shape and three feet are guaranteed to all touch the ground even if they are not perfectly aligned.

A cylinder is good for solid stuff also because it is a good compromise between stability (which would favor a wider base), shelf space efficiency (which prefers a tall straight cylinder) and getting stuff out (which would favor a wider mouth).

And indeed three feet make sense in an age of tables topped with rough planks.  If the feet are properly shaped, they still would allow the jars to be packed tightly on the shelf, with enough space between them to allow grabbing and pulling out any jar...

For liquids maybe one would want glass bottles.  Those are more easily made, by blowing, if they have round bottoms.  Which is the reason for the straw basket of the classical Chianti wine "fiasco".  Then one may want a metal or wood base to hold the bottle.

(IIUC that Italian wine bottle is the origin of "fiasco" in many other languages to mean "total failure".  Presumably by some story when someone wanted wine but got only the empty bottle...)

All the best, --stolfi