Mixing different companies porcelain

[Liz Swain]

Hi, I want to mix two different companies porcelain clays. One has shrinkage of  8% (+\- 2%) and porcelain that shrinks 12%.  One is colored porcelain and I am not fond of how it works with my handbuilding techniques. The other is my go-to porcelain. I want to mix in order to create softer colors. I know I should test but ,Any help would be appreciated before I do. Thanks. 

[Mark C.]

testing is the only way to know and they both need to be the same temp maturing clays for best results

[Morgan]

Outside of having to test it, wouldn’t it be easier to simply color with oxides/stains etc, your go to porcelain the exact color you are aiming for instead of having to deal with that? Food for thought.

[Rae Reich]

I don’t know how much of the colored porcelain you have, but it’s clear you don’t want to waste it.

Is it a small enough amount that wedging the whole batch seems doable?

If not, do you have access to a pugger?

Definitely, tests of the proportions of clays, colors, firing and shrinkage can be measured and assessed. At the least, you’ll have a small batch of special clay or your tests could result in a formula for your own blend.

[Kelly in AK]

Wedge a pound of each together. Make some pinch pots. Glaze to check for fit. See what happens. 

[Callie Beller Diesel]

If the mixture is homogenous, the shrinkage rates should wind up somewhere in between the 2 different points. You’re making a whole new clay body.