Here’s the newest round of slips for leather hard/stiff application. All but #7 will work for bone dry application. Not tested (yet) for bisque application. Fired to cone 10 flat in a hard reduction. Left side is super thick, right side is thinner. Clay body is a Hawthorn/Goldart/OM4 stoneware – nothing fancy.


#1 Greenware Slip: Grolleg Kaolin 40, OM4 Ball Clay 10, Custer 25, Silica 25
#2 Greenware Slip v.1: EPK 25, Grolleg 25, OM4 Ball Clay 10, Custer 25 Silica 25
#3 Bringle Slip: EPK 20, OM4 20, Neph. Sye. 25, Silica 30
#4 BS v.1: Grolleg 25, OM4 25, Neph. Sye. 25, Silica 25
#5 BS v.2: Grolleg 30, OM4 10, Neph Sye 20, Silica 20
#6 Coleman Clay: EPK 50, Silica 25, Custer 25, Frit 3110 5
#7 CC v.1: Grolleg 50, Silica 25, Custer 25, Frit 3110 5
#8 Porcelain Slip: Grolleg 30, OM4 8, Custer 30, Silica 30, Bentonite 2

The light is cheating these a little bit. #1,2, and 8 seem to be the whitest, with not much differentiating them. #1 seems to promote the best celadon blues, although timing is critical, because it cracked when applied to a bone dry tile. #2 seems to be a perfect middle ground in terms of versatility, cost, and whiteness. In my experience, the difference between a 50/50 grolleg/epk and a 100% grolleg clay body is negligible in cone 10 reduction. The case could be made that it really matters in oxidation – which is just now bringing to mind the need to test these in c6 oxidation.
My picks? For Whiteness:
#2__Greenware Slip___
EPK 25, Grolleg 25, OM4 10, Custer 25, Silica 25, 45cc Water, 5cc Darvan #7,
For Celadon Blue:
#8__Porcelain Slip___
Grolleg 30, OM4 8, Custer 30, Silica 30, Bentonite 2, 50cc Water, 5cc Darvan #7
I am looking for cone 10 Engobes and the recipes included in a hand written book above which cannot be seen easily. I wanted to download the recipes and print the page or pages but cannot be seen. HELP!!!!!
Hi Aubrey, an Engobe is kinda just a fancy word for a slip that goes beneath a glaze. There’s nothing that makes these any more or less complicated. The main difference is gonna be the whiteness, opacity, and how much they do or don’t shrink on application and firing. The right page is glazes (That didnt really work!).
#1 Greenware Slip: Grolleg Kaolin 40, OM4 Ball Clay 10, Custer 25, Silica 25
#2 Greenware Slip v.1: EPK 25, Grolleg 25, OM4 Ball Clay 10, Custer 25 Silica 25
#3 Bringle Slip: EPK 20, OM4 20, Neph. Sye. 25, Silica 30
#4 BS v.1: Grolleg 25, OM4 25, Neph. Sye. 25, Silica 25
#5 BS v.2: Grolleg 30, OM4 10, Neph Sye 20, Silica 20
#6 Coleman Clay: EPK 50, Silica 25, Custer 25, Frit 3110 5
#7 CC v.1: Grolleg 50, Silica 25, Custer 25, Frit 3110 5
#8 Porcelain Slip: Grolleg 30, OM4 8, Custer 30, Silica 30, Bentonite 2