Clay when bought premade comes in nicely bagged and boxed deaired blocks. This is very convenant and easily stored but costs some money if you are producing/using alot of clay.

Some clay bodies come in premixed but in powered form. This is a better bargin if you have the time to mix it yourself as you usually get a better price per pound and you don't have to pay to have moist clay shipped(moist means more weight to ship). The resulting clay will have the same properties as the premixed/prebagged clay but you have the advantage of price and controlling how moist the clay gets so it is the perfect wetness for your use.

Another option is to mix a clay body up according to a recipe. Many recipes can be found in books, internet source, schools, etc. Now why use a recipe? Well, the advantages of mixing a clay from raw ingredients is also one of economics. It will likely be even cheaper to mix your own using raw ingredient. Plus you have the ability to add more of this or that to customize the clay to your needs.

While digging and processing your own clay is not for everyone, I think every clay worker needs to visit an indigenous clay source at least once to learn about the source of clay and how it occurs in nature. A wall of clay is an impressive sight.

The Pros and Cons of Digging your Own clay

Pros:

It is cheaper
Easily customizable
Using local clay can be a marketing plus
A clay pit is pretty darn cool
Its a great excuse for a picnic

Cons:

It takes time
It is messy
You must test it to learn the clay's properties
It takes muscle(clay digging, hauling and mixing ain't for wimps)
You might not be in a location for good clay

I remember my first trip to the clay pit. My college professor(an adjunct) said if anyone wanted to learn where clay came from to meet up with her on Saturday for a trip to the local clay pit.

I was curious, I showed up, sadly only 2 other students did but the professor didn't waiver in her enthusiasism. Off we went on the 1/2 hour/45 minute car trip to the clay pit.

Over the river and thru the woods we did go. We parked on the side of the road and hiked into the woods bringing with us bags and buckets to haul the clay out with.

The surface at the top of the pit was mostly sand with quartz pebbles. Where ever a pebble and the clay met would be a small turret of clay with the surrounding clay washed away. Thousands on little castles formed the top edges of the pit, seemingly so magical.

We clamoured down into the pit. Exploring and admiring the clay walls surrounding us as we descended. The walls of clay were grey and pink with veins of brown and reds and purples.

We went the bottom and found a clay slick. The professor advised us not to come shortly after a rain as the walls would be too slick to make it down safetly and impossible to come back up. We had lunch of PB and J at the bottom and prepared to start working on getting some 'free' clay.

The digging really wasn't digging as we just grabbed big hunks, some larger than my head, off the wall. It went pretty easy tho we did run into a bunch of fire ants that were not too pleased with us disturbing their clay. We got us a bunch of 'free' clay.

Well the piper must be paid and the payment began, now we had to haul all this clay up the pit wall, thru the woods and load it into the cars.

We did it, tho we had to reshuffle clay bags to make them lighter so as to get them up the wall. I think we each scored about 200-300 pounds of clay that day.

I made many trips back to that clay pit while in college. It freed me of the financial constrants of supplies by being able to throw and throw and throw as much clay as I wanted for merely the price of a bit of sweat equity and a few bags of clay additives.

I now find myself in search of a clay pit in my new location, I will keep looking.

Testing is an important step after making your clay no matter if you dug your clay are followed a published recipe. There are many test to perform:

Test for Plasticity
Test for Throwability
Test for Shrinkage
Test for Porosity
Test for firing temp/cone range
and others