Ceramics Decorating Video: How to Mix and Apply Terra Sigillata for Burnishing Pottery

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To learn more about Sumi von Dassow, please visit: http://www.herwheel.com/

This clip was excerpted from Pit Firing and Burnishing with Sumi von Dassow, which is available in the Ceramic Arts Daily Bookstore.


  • Thank you so much Janice,
    I will definitely try this recipe, both with ball clay and red clay, I might like one better than the other…

    Thank you so much for taking the time to answer my question 🙂
    the best


  • Janice W.

    Kira, I have this recipe by Richard Hirsch from “The Complete Potter – Raku” for a red terrasig.
    OMG Ball Clay – 50grams
    Red Iron Ox – 50grams
    Deflocculent – 5grams
    Water – 400mls
    I would think that you could use a red powdered clay instead of the ball clay and iron oxide though. If you are in America, i think you call it Redart Clay? Some else may like to confirm what i have just said? Hope this helps a little.

  • Can you apply terra sigillata on bisque ware? Sumi says in the video she applies the terra on bone dry clay. Also does anyone know a recipe for red terra sig for bisque? I thought I could substitute ball clay with redart to have red terra.

    any help would be great thanks 🙂

  • Lynne A.

    thanx for the response…..by “clear”, I mean a “line” which appears to separate sludge from what should be terra sig. I do realize that there will be clay particles in the terra sig. Sorry for semantics confustion….
    Will shake up and give it another go…..thanks.

  • Donna K.

    question – what do you mean by clear? Do you mean that you do not have any sludge at the bottom? I do not think that letting it set for four days is going to work – the most I have ever heard is 22 hours and that was very specific – no more/no less. There are going to be clay particles in the liquid terra sig which why I am questioning what you mean by ‘clear’. I would shake it up again and let it set the 3 hours she recommends and then syphone off slightly above where you can see a line (you really must have a clear container for this). Just my 2 cents…

  • Lynne A.

    Thanks so much for the informative video. Decided to mix some up as per instructions & am perplexed by results. Used identical ingredients and measurements: 2100 G water, 25 G Darvan 811 & 1,000 G OM4 (mix my own glazes all the time…..allowed for weight of containers & double/triple checked my measurements as I always do)…..shook up mixture and four days later, have only 1/4″ of clear at top of mixture. It does not appear to be settling out and am wondering what might be going on?
    Lynne-Western Colorado

  • Just ordered the book today. I use to burnish and pit fire pots years ago only using river rocks so I am so looking forward to the terra sigillata version. Think they should market it premixed and ready to sell. Anyone interested in making sig in bulk then farming some of it out sign me up…. Tried making it with Calgon years ago but wasn’t happy with the results. Anyone using dry porcelain for the mix? Will start throwing while waiting for my book to arrive…..Was only able to see half the video then it stopped but the dry clay looked darker. Zach mentioned ball clay. Hope your day is beautiful…….from the foothills of California, Mary

  • Great subject matter! I learned alot, but had difficulty in clearly understanding what she was saying as the video sounded somewhat muffled. Spooky music was too loud. I’ll watch it a few more times though anyway!!

  • Elwyn F.

    Great excerpt. I bought Hot Damin Pottree DVD. by Don Ellis & Randy Brodnax Have gained a lot of Info. Encouraged me to sign up for their class in June 2010. Am considering buying this DVD. Hope it’s as good.

  • OM4 Ball Clay was used for the clay 1000 grams

  • I am looking for a supplier for Ferric Chloride.. Any thoughts??? Amazing video… Can’t wait to try it..

  • Ceramic Arts Daily is doing us a great service by showing us these segments. If you want to see the “Finished pot”, the next chapter, the recipes for that great glaze combination, etc. then buy the book or DVD.

  • Claudio L.

    I agree with several other folks, SHOW THE FINISHED POT please!!!!!!!

    Claudio, Japan

  • /firing-techniques/gas-kiln-firing/aluminum-foil-saggars-an-easy-alternative-to-traditional-clay-saggars/

    This is the article I was thinking of but I would not do the foil method in the electric kiln unless you but the piece in a clay sagger as well. If you have some old pots you don’t care for (you can use sewage drain pipes as well) put the piece you are firing, which has been wrapped with compustibles oxides, etc. and foil, inside the pot. Put a broken or ruined shelf of pot on top and seal the edges with clay. Fire to about 09 (I would research that more carefully – this is my guess). If you are getting smoke from this, then it wasn’t sealed well enough and that can damage your elements. I have not done this before. It is simply odds and ends I have picked up from reading so do beware.

  • desiree – do a web search for sagger firing. There is a good article recently posted online telling how to do what you want in an electric kiln. I would not do it however if you do not have good venting (JMO). I had thought the article was here but I can’t find it. As soon as I track it down I will post it.

  • I have a small eletric kiln, do you think is possible to do this process and teh smoke firing ?

  • Gregory B.

    Along with the horse hair, try sprinkling some sugar on the top part of the pot. Just useing the sugar alone can give a nice finish to the pot.

  • Thank you for this interesting extract ! It really convinces me of purchasing the book. I love to burnish, smoke fire etc. and would like to try terra sigillata too. If only I had a place to smoke fire or pit fire …

  • Zachariah D. S.

    Donna, I have read about many different T.S. mixes, the mixes that use the liquid Darvan and the Ball Clay don’t require as much settling time as mixes that use only water as the liquid ingredient. The more dry ingredients you use to mix the T.S. the longer it is recommended to set.


  • I would like to buy pre-made terra sig but have not had luck with my search for sources.
    Can you recommend a site for purchasing terra sig ?

  • My question is for those in the know on this subject – what I have read on making terra sig has a wait time of 22 hours and more than one ‘harvesting’ (taking the finest part of the clay off the top) and then evaporating it down to a workable thickness. This looks quite lovely to me. What would be the benefit of the harder and longer method?

  • Rhona and Joey – I think this is a taster. For more you would buy the book or DVD.

  • also, love to see the firing and finished product…

  • Very helpful video – but it would have been nice to know what dry clay was used to make the TS. It also would have been good to see the greenware pot when completely dry, and to see the finished product, after firing.

  • Firing terra sigillata to Cone 6 will take the gloss away. Cone 06 is about as high as you can go before you start to lose luster of the TS.

  • Shelly B.

    Glad to see it’s not difficult to make recipe. I ususally buy mine pre-made.

  • there is no reason to fire to cone 6. At our studio we 1st bisque fire it at cone 05, then radu fire it. As it is removed from the kiln we add horse hair to the hot pot, and that will leave beautiful black line on the pot

  • If you were to fire the pot to cone 6, would the terra sig treatment still show?

  • Thank`s for the video! I got your book. That is really a good book!

  • I would assume there is no glaze fire…. She is pit firing with raw ingredients like copper carbonate, ferric chloride, sawdust, steel wool, etc…
    I personally bisque to c 010 to keep the clay as porous as possible so it will absorb more smoke etc. in the firing

  • You said it was a cone 6 clay body. What temp do you bisque fire and then glaze fire?


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