The secret to cool bodies and glazes is alot of testing. But how will you be able to learn from that testing without a good place to store the recipes? Document the successes and failures? Do it in your account at

Ravenscrag Cone 6 Floating Blue

Code: GR6-M
Modification Date: 2019-03-13 14:58:36
Member of Group: RV6

Plainsman Cone 6 Ravenscrag Slip based version of the popular floating blue recipe. It can be found among others at

Ravenscrag Slip40.034.5%
Ravenscrag Slip 1000F Roast39.033.6%
Ferro Frit 313420.017.2%
Ferro Frit 312410.08.6%
Iron Oxide2.01.7%
Cobalt Oxide1.00.9%


David Shaner's cone 6 floating blue has been used for many years by thousands of potters. However the base (the clear to which the colorants are added) is 50:30:20 Nepheline Syenite:Gerstley Borate:Silica. It has serious issues (including slurry gelling because of the partially soluble Gerstley Borate and Nepheline Syenite, consistency and supply issues with Gerstley Borate, susceptibility to blistering and higher thermal expansion because of the high feldspar content). As a consequence most users thus have had a love-hate relationship with the recipe.

This employs an alternative base recipe into which the iron, cobalt and rutile have been transplanted. The GR6-A 80:20 Ravenscrag:Frit base has been conditioned with a further 10% frit addition to get more crystal development and variegation. This base eliminates the solubility and consistency issues and produces a glaze of lower thermal expansion.

Although more expensive to make than the GA6-C Alberta Slip Rutile Blue (because of the cobalt), this one produces the rich blue without needing the slow-cooling firing schedule. The recipe originally had 80 parts raw Ravenscrag powder but we have adjusted it to 40:39 raw:roast (according to instructions at Feel free to tune the raw:roast mix to get the exact slurry properties you want. More roast makes the slurry shrink less, dry faster and more powdery; more raw makes it shrink more and dry harder.

For mixing instructions please see the master recipe, GR6-A.

Out Bound Links

In Bound Links

XML to Paste Into Insight

<?xml version="1.0"?>
<recipes version="1.0" encoding="UTF-8">
<recipe name="Ravenscrag Cone 6 Floating Blue" keywords="Plainsman Cone 6 Ravenscrag Slip based version of the popular floating blue recipe. It can be found among others at" id="114" date="2019-03-13" codenum="GR6-M" altcodenum="G2917">
<recipeline material="Ravenscrag Slip" amount="40.000" unitabbr="kg" conversion="1.0000" added="0"/>
<recipeline material="Ravenscrag Slip 1000F Roast" amount="39.000" unitabbr="kg" conversion="1.0000" added="0"/>
<recipeline material="Ferro Frit 3134" amount="20.000" unitabbr="kg" conversion="1.0000" added="0"/>
<recipeline material="Ferro Frit 3124" amount="10.000" unitabbr="kg" conversion="1.0000" added="0"/>
<recipeline material="Iron Oxide" amount="2.000" unitabbr="kg" conversion="1.0000" added="1"/>
<recipeline material="Cobalt Oxide" amount="1.000" unitabbr="kg" conversion="1.0000" added="1"/>
<recipeline material="Rutile" amount="4.000" unitabbr="kg" conversion="1.0000" added="1"/>
<url url="" descrip="Recipe page at"/>

By Tony Hansen

Feedback, Suggestions

Your email address


Your Name


Copyright 2003, 2008, 2015, All Rights Reserved