QotW: When buying clay bodies, what characteristics do you look for in the clay? Especially when buying a new body you have never used before.

[Pres]

Going through the clay charts at Standard Ceramics lately, and thinking back to all of the interesting thoughts and discussions I have heard over the years. Wife says: Oooh!  that's a pretty color why not that one? Hubby: stains everything, absorption is too high. . . glazes wont fit it.  Wife: Aww you could do it. Hubby, Not interested! Wife: Oh. So how do you decide on a clay body, is it price, or fired characteristics, or working characteristics, or even just because you always use it, or is it word from others passed along?

QotW: When buying clay bodies, what characteristics do you look for in the clay? Especially when buying a new body you have never used before.

best,

Pres

[LeeU]

The look of the fired unglazed clay is my essential criteria. Unless I'm checking out a new-to-me black/gray, I go to great lengths to avoid staining - usually go for whitest/lightest bodies, but they can't be soft/slippery. I usually get somethign with a bit of tooth/grog/sand, recommended for handbuilding. I don't care about absorbsion  or shrinkage for what I do.  Suppliers tend to have helpful, knowledgable, customer service people who have never steered me wrong. At the moment I am in love with Dragon Fruit, from International Clay & Mnerals Co. ICMC   Very light gray with fine speckles and feels like stone...makes for some interesting contrast with glazes (but not for total coverage-that just wastes it's beauty). 

[Hulk]

Good question!

I feel and think (both!) that I'm just starting out with trying and choosing clay bodies ...I've found three, err, four clays that I like, three of which a nearby* supplier carries.

I still like periodically rotating from white to red to buff/brown.

All the factors Pres listed apply for me, excepting "word from others..."

For white and buff stoneware, I like low absorption (less than 1% preferred, else 1.5%), almost never has "gassy bits**" and tolerates a cone or more overfiring without issue.
For red stoneware a bit higher absorption is ok (unless/until I find something better), almost never has gassy bits, tolerates just over a half cone or so overfiring.
My low COE liner glaze has to fit Very Well, and my colored glazes have to fit well.

The clays I've tried and won't go back to have one or more of these characteristics: expensive, high rate of gassy bits failure, my low COE liner glaze doesn't fit (crazing), misbehaves horribly when overfired a wee tiny bit (fizzing, bubbling, turns purble, melts/slumps), absorbs water too quickly while working (giant globs of absorbent grog in there), is just too sandy/lumpy and or the sand is sharp (is there any good reason for sharp sand in clay?), varies considerably/intolerably batch to batch.

When next buying clay (almost certainly the same three clays I'm using now), I'll want to know if the recipe has changed since last purchase.
There's the talc change thing, and I've already had a "this is Totally Different Clay" experience with another vendor's product. Even if assured it is same, I will test! !!
Likely I'll also get a fifty-pound box of something to try, which is how I discovered the speckled buff that I really (really) like.

I prefer the clay right out of the bag to be a bit softer/wetter than I want to work with, which is easily remedied by a turn on the wedging board.
Somewhat related, I don't want clay right out of the store to be "old" already - fresh, please; nor do I want clay that's too stiff/dry for my taste.

Stacking the boxes together in a shady and cool spot, then covering tightly with a tarp seems to help keep the clays "young' ...now I wrap the boxes with moving wrap before stacking them up, seems to help. The moving wrap is like a gigantic version of the cling wrap used to wrap food.
 

*the nearby vendor is just under 100 miles away, IMCO in Sacramento. They make a white and red that I like, and they carry a Laguna product that I've tried and like. Another California clay vendor has a white and red stoneware I like, but they are further away, and I like the nearer vendor's clays a bit better, not Just because they are cheaper, no, the white is more consistent, and the red has better working properties, tolerates overfiring better, and is less absorbent ...and their clays are less expensive.

**where there's a large pit/hole in the glaze, which I'm guessing is due to a large piece/chunk/bit of something that off-gassed enough to create a volcano-like effect that's too big to heal over. I'm willing to tolerate this when it doesn't happen very often, at all, like one of twenty wares - not so much one of seven.

Added: That Dragon Fruit clay has been whisperin' to me!
 

Edited August 28, 2023 by Hulk
Dragon Fruit, IMCO clay

[Min]

After having a colossal waste of both time and money trying clay from a couple different manufacturers this year (that I haven't used much before) and getting crap clay that included bits of metal in one line and contaminated materials in another I went back to my original supplier and my tried and true smooth white(ish) clay. First and foremost is having trust in the quality control of the clay supply I use. Tony Hansen is the clay tech for Plainsman, I have used their clays for many years and happily went back to using it after this brief foray into other suppliers, can't afford this frustration again. Second I want a claybody that has an absorption of under 1.5% for the majority of my functional work. (I check the absorption figures myself every 6 months or so) It's a plus if the clay is nice and soft when I purchase it so I try not to buy it if the suppliers stock is running low and it's older inventory they have on hand.

[Mark C.]

I rarely try new bodies and stick to ones i have used for many decades. I have tried a new to me porcelain in past  few months to see if my rutile pitting was body related. I liked the Ardvark Nara Porcelain but at twice the cost it was not worth it. The pitting was not cured 

[Kelly in AK]

Probably absorption is my number one concern, followed by how it looks after soda firing. Generally, if something works I stick with it but occasionally try new things. Laguna's B-mix 5 is working well, I fire to cone 6 or slightly hotter and it gets very tight. It does warp if taken too high. And it's more expensive than I would like, but it really works well in soda.   

[Denice]

Over the years I have had two different clay's that I loved discontinued.  I dislike a clay like  B-Mix it feels like cream cheese.   I like one with enough body that I can throw and handbuild with it,   I switch back and forth with  red speckled and white and dapple with a tan now and then.   Denice