There are differences in clay bodies, as David points out.
Terracotta is a claybody made up of a variety of clays that mature at a low temp when fired as David said between cone 06 and cone 12. Terracotta is exclusively used in utilitarian ware like plant pots and sculptural pieces.
About Indian pottery. There are few examples from northern tribes.Storage containers used by Lakes tribes were tightly woven reed containers.
Southwest tribes rarely dealt with the prolonged freezes experienced by northern tribes.
I have zone envy for gardeners who can leave containers out all year round.
As Sheryl said above,Terracotta can be left outside in warm climates,all year round.A light frost wont hurt it.
When terrecotta is left outside in northern winter ,especially filled with dirt.The rain and snow keep the walls wet as the dirt holds moisture also. These wet walls freeze under prolonged months of freezing and thawing in winter temps of 20* and lower.
The water freezes and expands and opens the walls of the pot and it fractures and just crumbles.
I dont buy clay pots anymore and I use a plastic pot liner in the terrecotta pots I have because the terrecotta draws moisture from the dirt in contact with bare walls. I water less with plastic liners.
Terracotta is the cheapest clay body on the market compared to Stoneware and Porceline. There are cheap manufacturing methods too. Hand thrown on a wheel would be more expensive but it's my hunch most Terrecotta now id mass manufactured in "press molds " if not poured into "slip molds". The profit margin is really high using these methods. $100.00 for a terrecotta pot is just out of sight. Many customers like the look tho.
Pit firing is still done ,GF uses this method to produce expensive sculpture.No fuel costs. Native Americans and Mexicans use this method because there werent and modern fuels.
There are still areas in Mexico where they pitfire but use old oilfilters as fuel.
I love the smoked look even tho it doesnt last long if pieces are left outside.
GF Website
http://www.janjacque.com/
GF pitfiring a load of sculpture
