Porcelain for raku/pitfire

[ATauer]

I will be starting to use a porcelain recipe I developed myself in most of my work- most of which is sculpting, including a lot of large scale sculpture, but I also want to use it in raku and pitfiring. I know the hazards with it- 90% of the time the clay I use is made into paperclay, and paperclay is noted for doing well in raku and alternative firing especially with porcelain. I also have half my silica as pyrophyllite which should help with the thermal shock. I am also considering sometimes wedging porcelain with raku clay, as I do also use raku clay as well it just isn’t as smooth as I would like particularly for things like naked raku. What I would really love is to be able to go to Great Lakes Clay which I have read about in so many books and use their raku porcelain. It is a real shame they closed as I would be willing to drive to Chicago to get materials I can’t get locally. When they closed did they publish any of their recipes or even give any hints into how they made such a beautifully white, smooth, grog free raku porcelain?  I’m still experimenting with my porcelain recipe and it will probably take months of tweaking before I am completely happy with it, but my goal towards the end of the summer is to also develop a white stoneware recipe that can be used for a variety of things including as a raku body, while somehow magically managing to have it be actually white. But I’m excited by the challenge. If anyone has any idea about the recipe Great Lakes used, if they sold it to anyone, if anyone even just was told a vague story of some of the things in the recipes…anything would be helpful. Thanks!