Blue Green/Copper Red Glaze Recipe, Cone 6 Oxidation or Reduction

Blue Green/Copper Red Glaze Recipe Cone 6
Glaze Material Percentage
Talc 3.30%
Whiting 14.29
Frit 3134 (Ferro) 13.33
Kona F-4 Feldspar 46.16
Edgar Plastic Kaolin 6.40
Flint 16.52
Total 100.00%
Tin Oxide 2.24%
Zinc Oxide 4.37%
Black Copper Oxide 1.07%
  • Carmillia K.

    how can i reproduce the beautiful eggshell glaze in an electric kiln if red is not possible in oxidation? need help please

  • Lawrence W.

    I know that the plate illustrating this article was sprayed with multiple layers of glaze. Does anyone know where I can find a description of the various glazes and their application sequence? Its original source, ceramics monthly October 2000 is apparently no longer available.

  • lyric m.

    I’m needing a temmoku brom/black for cone 6 ox. Any ideas?

  • lyric m.

    Thanx everyone! Been a potter for 40 years and have learned some new things tonite. I’m re-visiting my cone 6 roots once again and needed some help.

  • Kelly P.

    Hey Pham,
    I think you mean Metal Reduction with copper?? Did you try the formula at the top?? Read the previous post for Oxidation if you are working in Oxidation. Good luck.

  • Kelly P.

    Hi Alina,
    The Rasberry is a little redder on Porcelain but still looks more purple to me. There are a lot of little clues to reds on this blog but you will have to experiment and put them all together. A Red Ox Recipie in all honesty wouldn’t do much good because your clay combo and chemistry will never match the authors. I think Steven had some good advice with Spanish Red Iron Oxide. Another trick to reds is the addition in certain glazes of Zinc or Tin Oxide. These can be tricky and in certain glazes make a mess, so be very careful. Start experimenting with these ideas on a rich brown that already has a reddish cast. Some of the Mason stain instructions will give you good info on what chemicals work and what to avoid. Don’t give up!! I am still working on it but am getting very close!!

  • Alina H.

    I tested the raspberry red from the book “Mastering Cone 6 glazes” and it too came out very purple for me. At first I thought I’d mixed it wrong and added too much chrome, so I mixed it again with the same result. Did anyone have it come out as red as the book? I too use Laguna’s Bmix as my clay.

  • Pham N.

    Hey Kelly and everyons, I’m a student. I am working at mental deduction glaze ( CuO ) I tryed some fomula, but not any success. Can you help me 🙂 ?

  • Cynthia S.

    This comment is year’s late, but I wanted to respond to Tamera’s comment that The RR Mastering Cone 6 Glazes “Raspberry Red” doesn’t look like it does in the book, but looks more purple. I’ve used that glaze a lot, and it looks purple if you apply it thick. If you want the red apply very thin on a very white clay body. I use Laguna’s B Mix.

  • Subscriber C.

    I think he wants to know about whiting. It’s calcium carbonate = carbonato de calcio.

  • Kelly P.

    Anybody translate Simones comment? I think he is asking for a substitute material for Ultra Pax or Super pax?? not sure of the material. He is unable to get these in Brazil. I wonder if Tin Oxide is Available??

    ¿Alguien traduce el comentario de Simones? Pienso que él pide un material de sustituto para Pax extremo o pax súper. Él es incapaz de conseguir éstos en Brasil. ¿¿Me pregunto si el Óxido de Estaño está Disponible??

  • Simone M.

    Sou brasileira e há muito tenho visto receitas que utilizam como matéria prima o badejo. Porém aqui no Brasil já perguntei para todos e ninguém soube me dizer onde encontrar ou como substituir.
    Simplesmente ninguém aqui conhece esta matéria prima.

  • Beverly R.

    Emily’s Purple is a great glaze in our oxidation cone 6 kiln. It is a semi-matte and a little mottled which gives it more interest.

  • Kristen C.

    I’m on the hunt for a oxidized red in a gas kiln (some reduction will occur)
    Elizabeth on June 9 you mentioned Randys’ Red w/ 20% Spanish RIO as a great oxidized red. Can you provide the recipe? Or anyone else have it?

  • Charna S.

    does emily’s purple work in oxidation?

  • Richard B.

    This is a much truer purple and holds perfectly in reduction as well.
    Emily’s Purple
    Custer Feldspar: 36.60 Grams
    Gerstley Borate: 19.40 Grams
    OM-4 (Ball Clay): 11.80 Grams
    Talc: 15.10 Grams
    Silica: 10.80 Grams
    Dolomite: 6.50 Grams
    Zircopax Plus: 10.00 Grams
    Cobalt Oxide: 3.00 Grams
    Total: 113.20 Grams

  • Maura F.

    Hi Kelly,

    THANK YOU! This article will be extremely helpful for me. I really appreciate your interest and effort helping out beginner potters. I am also going to look at the books by Zakin and Hoppers which you recommended in an earlier post.


  • Maura F.

    Hi Kelly,

    Thank you for your note. My kiln does have programmable ramp modes, and so I will study the manual carefully and try the slow cooling. I am making some of the glazes now which are in Hesselberth and Roy’s book and am very excited to begin testing them. Thanks again!

  • Kelly P.

    hey maura,
    If you go to the Ceramics Art Daily “How to Add Color To Your Ceramic Art.” You can find under the “Many Faces Of Iron Ox.,” detailed instructions on slow cooling that includes temps and holding times. Nice bit of information that will apply to a lot of other glazes not just Iron based.

  • Kelly P.

    Hi Maura,
    If you have a Matte Glaze that requires a slow cool to develop micro crystals then you need to program for a slow cooling period (not a hold) after you reach your temperature.
    In my kiln firing that gives me an extra long period between 2100 degrees to 1500 degrees. I have the old fashioned kind that just uses switches so I set them at half power which provides enough heat to keep the temp from dropping too fast. I have set up an old Skutt program but can’t remember if they call it “Ramping” down or something else in the manual. Your Skutt manual should actually suggest a way to slow cool, so give the whole thing a good read. If anyone else has a Skutt Program and knows how to set it for slow cool can you pipe in here and help Maura out??
    Good luck.

  • Maura F.

    Hi Kelley,

    Will you please let me know what you mean by dropping your switches to M in order to hold the cooling time? I can do this with my kiln, but do not know how, as I am new to both pottery and firing. I have a skutt programable kiln. Thanks for your help,


  • Kelly P.

    Thanks for the hint on the Spanish Red. Robin Hopper does not even list it in his glaze book. Good disclaimer on glazes found in a forum. I agree they should be taken as test ideas only.
    I have to say though, coming from a less than ideal clay and glaze background, I do find some of the tidbits of wisdom freely passed out very helpful in my hours of struggle to come up with a stable, safe and beautiful glaze.

    Reds in oxidation are rarely discussed in the plethora of books that I have on the subject. So every little bit helps to direct my search. Thanks for the tidbit.

  • Steven S.

    @ Suzon, the eggplant glaze is really high in manganese Dioxide and also high in Cobalt Oxide. You probably already know that, but you might want to mention when posting if others intend to use for functional usage.

    @Alvin, you can get red in cone 6 oxidation, both in terms of an iron red and a tin/chrome red. The one presented in RR/JH cone 6 book isn’t a very good one.

    If you want to make one with red iron ox. use spanish iron instead, it is richer and will do a better job. Also, you’ll need to fire down the kiln.

    If you want to create a nice tin/chrome red then be careful what sort of clay body you use, it can make all the difference. A great red on a buff clay body, won’t look very good!

    What is sometimes bad about these forums is they are a poor substitue for the hundreds.. I mean thousands of hours of work it takes to understand glazes properly from application to the chemistry that makes a glaze work. I hate to say it, but if you aren’t willing to really put in the time, you will likely have pretty average results.

  • Janice W.

    Just read all the above and thanks to everyone for contributing the information. Very helpful.

  • Kelly P.

    Paulraj & Charlie,
    You will need to substitute with a Laguna borate or possibly go to a Ferro Frit 3134. Try the Ferro Frits that usually contain higher borate content. Charlie the glaze at the top is in percentages but think of them as grams. You will need to multiply by 75 to get 3 gallons of glaze in a 5 gallon bucket. I usually round the percentages that are under .5 down and then the ones that are above .5 up. So talc would be 3 % and Flint would become 17 %. You should still come up with a base of 100. Convert this to grams and multiply each ingrediant by 75 to come up with a 7500 gram batch of glaze that makes 3 gallons. Make sure you do a test batch of at least 200 g to figure out if you like it or not. Just a note of caution, the glaze at the top is not oxidation fired but reduction fired to get the copper blue and red.
    Hope this helps.

  • Charlie B.

    The percentages that you show for the glazes?? Does that mean that much in pounds to add or what. Sorry for the stupid question. Just wondering how to make a good glaze and would like to try the one at the top for cone6 in an electric kiln. How much water do you need to add with the mix is my next stupid question??
    Any help would be greatly appreciated.

  • Paulraj R.

    I am new to this page & realy happy to have these abundance but in India gerstley borate is not available. what is replasment.THANKS.

  • Suzon M.

    Tamera……. Hope you enjoy! I know this adds up to 115 without colorants, but it does work. I haven’t recalculated to 100.

    Eggplant Cone 6-10 Oxidation or Reduction

    F-4 Soda Feldspar 45
    Gerstley Borate 10
    Dolomite 10
    Talc 15
    Ball Clay 5
    Silica 30
    Cobalt Oxide 3
    Manganese Dioxide 5

  • Suzon M.

    Tamera, I know all about budget money as I teach pottery classes at a community college.
    We are out of money until August.
    I’ll get my best cone 6 recipes together and post them or send via e-mail whichever you prefer. My recipes are at school so I will get them tomorrow and post tomorrow night, late, as I have a class tomorrow night also.
    The purple is a beautiful satin, medium purple. Not glossy, even with a fast cool down. And….it is stable! No running off the pots!
    It feels so good you just want to keep rubbing your hands on the pots!!…….Suzon

  • Suzon. I will take anything you can give me. We ran out of budget money for this school year so I wasn’t able to try any of the ideas above but a new school year is coming soon= new budget money.

    Thanks in advance, Tamera

  • Suzon M.

    Tamera, if you are still looking for a good purple cone 6 glaze recipe, post again. I have a beautiful one that I would be happy to share….Suzon

  • Elizabeth E.

    For electric kiln red, you might try Randy’s Red which has 20% Spanish red iron oxide. Of course it’s not the Chinese blood red of the reduction glazes, but its a nice etruscan red that goes greenish when thick, and breaks black over rims.

  • Kelly P.

    Hi Wil,
    That is a lot of Soda Feldspar. Does it craze much? Are you using this same recipe with your oranges and Mason Stains??
    Thanks for the info. Nice work and website.

  • Subscriber T.

    I use a basic clear with high amount of NC-4 or G200 (soda spar) and about 17 whiting, 10 silica, 6 epk, 5 zinc with any of the red Mason stains and get great reds at cone 6 oxidation on most porcelain bodies. Although, the downside to this is that the glaze needs to be sprayed on as it dries extremely fast and is prone to revealing uneven application and brush marks..

    You can see examples of the glazes at

    Cheers, Wil

  • Cheryl P.

    Does anyone have some advice on crystalline glazing. In particular a decent firing ramp for cone 6. I know from reading that this process is quite unreliable but I do think it is worth the effort and the many failures!! Cheryl

  • Subscriber T.

    Get the book mentioned above “mastering cone 6 glazes by Hesselberth and Roy. There is another one by Richard Zakin called Electric kiln ceramics which is really good. Lots of recipes in both. Ron Roy has quite a few glazes that will break away and create a Hares fur pattern. Titanium dioxide and rutile will give a great deal of visual texture to many glazes. I think my favorite for understanding glaze chemistry is Robin Hoppers “The Ceramic Spectrum” book. It reads well and gives you all the information you will ever need to master the art of making your own glazes.

  • Gail F.

    Can anyone give me advice on how to learn to make my own cone 6 oxidation glazes, I’m new at this ceramic stuff, self taught, any help will be appreciated, I want a glaze that breaks shiny multicolors

  • Wow!! Thanks a million Kelly. I will let you know how it turns out.

  • Subscriber T.

    Hi Tamera,
    This is a glaze from Roy and Hesselberth’s book “Mastering Cone 6 Glazes.” This is the recipe for “Rasberry” but it does not come out that way on the porcelain or buff that I use. It is a Pale Purple to me.

    Whiting 20
    Nepheline Syenite 18
    FF 3134 14
    OM-4 Ball Clay 18
    Silica 30

    Green Chrome Oxide 0.2
    Tin Ox 7.5

    Ron Roy cautions against using to much chrome oxide to deepen the color since to much chrome will create a very ugly green glaze. This is a semi gloss when slow cooled for two hours after reaching cone 6. I just drop all the switches to M and leave it there for two hours. This glaze will be very shiny if you just let the kiln shut off and cool down. I have mattes that require me to slow cool. This glaze will work either way.

    Hope this helps.

  • Does anyone have a recipe for a red glaze in an oxidation firing?

  • Can you give the purple glaze recipe PLEASE. I am a first year high school ceramic teacher and my students are begging me for purples and reds. I’ve given up on red but if you have purple i would more than greatly appreciate it. Should I give you my email address?

  • Subscriber T.

    Yes, I ment Steven Hill. Sorry about that.

  • Subscriber T.

    So how do we get red or sienna in electric oxidation?? Stephen Hill is doing some amazing things at Cone 7. Anyone have any clues for us??
    I have a purple glaze but that is as close as I have come with it.

  • Alvin T.

    Rhonda you need reduction to get red. If you fire in an electric kiln which is oxidation
    firing then you will end up with green/blue no matter what cone you fire to.


  • Rhonda D.

    Have tried this and several other red glazes with no luck. All come out green. I have even tried clear over the red glaze to help keep color true. I use mid fire clay and fire electric to cone 6. Would firing to cone 8 help?

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