Tea Pots, Part II
Tea pots have three kinds of screens to filter the tea before it is poured out of the spout. There is the flat "Net", a piece of clay that was laid flush with the inside wall of the tea pot that has 5 or 7 holes to filter the tea. There there is the concave "Ball" that also filters the tea, this is an older and more traditional style, but the oldest style of hole is the "One Hole" - or, it has no net at all. Only older pots and replicas have this. Also interestingly, older pots are lighter in weight because artists had better sand to work with and much more time to work it. It was cured and processed for a longer period of time.
Today there are two major factories that produce tea pots: Factory 1 and Factory 2. They were both begun in the 1960's. Factory 1 was founded to specifically make tea pots. Factory 2 was a general clay factory, making pots and later, when Factory 1 was overwhelmed, Factory 2 picked up the slack and started making tea pots too. Now both factories produce good pots, but often the design details of Factory 1 pots are preferred by collectors.
A good way to understand the concept of breathability in clay tea pots is to fill them with hot water and smell the side of the pot. The stronger the smell, the larger the pores in the clay. This is a very interesting experiment especially with pots of the same clay. You will notice a slight difference in fragrance. Tea pots from Factory 1 smell like a hot sidewalk or a hot stone. To me, it is the smell of a hot iron on dry cotton. Factory 2 is a more unique fragrance, it smells like hot sand and a bit horse-barn-y (seriously).
To sum up, when looking for a good tea pot you want to use, consider the following: Craftsmanship - does the pot look like it's well made and balanced; is there enough detail: does the bamboo have segments and leaves? Do flowers have distinct petals, leaves, branches and look lifelike? When you look inside the pot, at the bottom, do you see "sparkles" or pieces of sand? How many? The more, the better.
Start there, look at pots, consider them before you buy, and play with the tea pots you have. When you're ready to invest, choose a pot that fits your personality, budget and is a good investment piece, a great tea pot can last you your whole life.