Difference between Porcelain Slip and English Porcelain Slip?

[Nookkemstudio]

I usually buy regular porcelain slip from my ceramic supplier but they only had English Porcelain Slip in stock when i went last time. Are there any differences other than the color? I know that English Porcelain comes out more white.

I heard from somewhere that English Porcelain has a tendency to warp more and that it requires thinner walls but I can't find any information online to confirm that. Does anyone know if there are any differences that I should know about? 

Thanks in advance!

[Min]

I haven't done a huge amount of slip casting but have used both grolleg (English kaolin) based slips, EPK based slips and a mix of the two. I found the grolleg based ones are both whiter and more translucent when thin.  I did have to fire about 1/2 cone cooler than I normally do for mugs or the handle weight would pull them out of round. (test for absorption if you do this)

[Jeff Longtin]

I've worked with lots of different slips and Min's comments are correct.  The slips I've worked with were not specifically identified by their clay type but from experience I've learned that the whiter slips, generally speaking, are made with grolleg kaolin while the less white slips are made with EPK, or #6 Tile kaolin.

I've also noticed that grolleg based slips generate mold more easily than the other slips.

I've not found working properties to be all that difficult/challenging. (In fact I like porcelain better than stoneware.)

Good Luck.