Wednesday, August 19, 2015

Saggar Firing

I've heard it said that there are two types of ceramic artist, those who love the process and those who love the fire... I think I'm definitely a fire lover! Seeing an effect developing before your eyes is amazing, throwing your work out to fate and watching the random results can be equally disappointing and satisfying. But when something works out just as you'd hoped, it makes all of the failures worthwhile!

Saggar Fired Lentil

So continuing my love of all things flammable, I've been trying out a new technique, Saggar firing. 

A Saggar is traditionally a ceramic box or container in to which your work is placed to protect it from flames and kiln debris during the firing process. But during the 20th century it has been used by potters to create a reducing atmosphere. Filling the areas around your pots with organic materials can produce some amazing effects. 

Triptych by
Saggar fired owls by Christopher Stiles

After some research, I decided to have a try at creating a mini version for beads. But rather than building a box to fire. The technique I tested used plain tin foil to wrap your items, and rather than glaze, the pieces were treated with Ferric Chloride. 

First a warning!!... this technique creates toxic gases and uses corrosive chemicals. As well as my usual safety precautions of gloves, face shield and long tweezers and tongs to protect me from the hot beads, I also wore a full face respirator rated for toxic gases. The gases can be produced through all points of the firing, so it's not something you can do indoors. But don't let that put you off, common sense and protective clothing will make this a safe technique to try out!

Making the beads

I started out with some bisque fired beads and pendants. These were dipped in to ferric chloride, and when dry, given a second dip. Ferric Chloride is corrosive, so care should be taken to wear gloves and protect surfaces. 

Dipping in Ferric Chloride

They were then wrapped in tin foil with various organic items. For my experiments, I used feathers, grass and leaves.

Wrapping in foil with organic material

Once they were all wrapped, they went in to an old terracotta flower pot to keep them all together during the firing. The tin foil disintegrates as the temperature goes up and it's hard to take the pieces out in one go while they're hot.

Hot from the kiln

They were fired up to 700oC and removed from the kiln. I used raku clay to make the pieces, it is extremely tolerant to thermal shock which means I could spray them with water to cool them and bring out the colours. Be careful if you try this with other clays as there's a chance they will crack or explode! I have safely tested my own clay to check I can do this!

I love seeing the colours bloom and I was over the moon with the results, particularly the feather designs. During the firing the organic material burns away and the reaction between the carbon, the foil and the ferric chloride gave me some amazing effects leaving a ghost of the item in the clay.

Shadow of a feather

As the beads were bare clay, I sealed them using an acrylic spray which enhances the colour and protects them.

Gorgeous Effects!

I love this simple technique that gives you such varied and amazing results, this was definitely one of the more satisfying things I've tried and repeats well, but with different effects on each piece. Some turn out darker, some lighter, some just leave a halo of the item. I think that the gaps between the foil and the bead affect how the image transfers... I will definitely be trying more to see what other interesting effects can be produced!


  1. Wow, that's a fun technique and I love the result!!

  2. What wonderful results! These are great, as ever!!

  3. I make raku jewelry. Just last night I decided to add saggar firing to my firing techniques. Thank you for your timely, inspiring post!

  4. You do indeed love to play with fire. the results of your testing are absolutely wonderful . I love the ghost feather effect . and the colours are so delicate .can't wait to see more.

  5. What gorgeous beads Caroline, your generosity of spirit and sharing of processes and ideas is so uplifting. The end result, is of course, fabulous as usual. x

  6. Another fascinating idea from your huge repertoire Caroline!

  7. Very interesting results. Thanks for the inspiration. Though I likely will never make ceramic beads, your post and detailed explanations are inspiring


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