A saggar is a small kiln inside the kiln, and you decide what the weather is in it.

A saggar is a sealed container that goes inside the kiln. You pack it with a bisque pot and a handful of things that burn or fume, and the pot gets colored by whatever is closest to it. Wherever a material touched, you get a mark. Wherever it did not, you get pale clay.

Sawdust makes the blacks and greys. Copper makes the reds and turquoise. Salt makes both of those sharper. Almost everything in the long version is a variation on those three.

What you need: a smooth, low-bisqued pot, heavy duty aluminum foil, sawdust, table salt, copper carbonate, gloves, a respirator, and a kiln outdoors that you can hold at about 1350 degrees F.

You are reading the Nutshell Version. The switch above opens the long one, which covers the cutaway diagram, the three kinds of saggar, terra sigillata, a twelve-material reference table, firing temperatures and nine ways this goes wrong.

Some of this genuinely cannot be written down. How much sawdust actually looks like too much sawdust. How loosely a foil parcel wants to close. What the foil looks like at the moment it has stopped being shiny, which is the cue that tells you to stop the firing. You have to watch a person do those, and film is unbeatable at exactly that. It is why there are seven videos on this page.

But film is a miserable reference. You cannot skim it. You cannot jump to the line about how hot the salt has to get before it does anything. You cannot scrub a timeline with gloves on, and you cannot search it a month later when you have forgotten whether the copper goes on the pot or in the bed. Text holds still. You set the pace, you re-read the one sentence you needed, and setting your own pace turns out to be most of what makes a thing stay in your head.

So this page is deliberately both, and it is built to be held up on a phone next to a packing table. The lists are short on purpose. Nothing loads from YouTube until you press play, which also means it opens fast on studio wifi, and there is a print button at the top if you would rather have paper that does not mind dirty hands.

None of these videos are ours. Every one is somebody else's work, credited by name and channel, and pressing play sends the view to their channel where it belongs.

Terra sigillata is clay separated down to its very finest particles and suspended in water. Brushed thin onto bone-dry clay and buffed as it goes matte, those particles lie flat and lock together into a surface with a low sheen. It is not a glaze and it does not melt. It is just clay, arranged tidily.

That tidiness is what changes the firing. On an open, unpolished surface, carbon and salts sink in and diffuse, and every mark spreads a little into its neighbors. On a closed, polished surface they sit near the top, so a line of copper wire reads as a line rather than as a smudge. That is the entire reason people bother.

How it goes on: two to four thin coats on bone-dry work, letting each one lose its wet shine before the next. Buff each coat with a soft lint-free cloth, a chamois or the smooth side of a plastic bag while it still looks slightly damp. A banding wheel makes the coats even and is worth the setup. Then bisque low as usual.

Burnishing with a stone is the older route: rub the leather-hard clay with a smooth pebble or the back of a spoon until it shines. It gives a deeper polish than sigillata and it costs a great deal more time, and it only works on smooth un-grogged clay. Most people use sigillata because it can be done on bone-dry work in a fraction of the time.

One thing that catches people out: both surfaces are fragile before firing, and both take fingerprints permanently. Handle the pot from the inside or with clean cotton gloves from the moment you start polishing.

Let it go completely cold first. Foil holds heat, it is sharp when it tears, and a warm pot going into cool air is still a thermal shock risk. There is nothing to be gained by opening early except a cracked piece and a burned hand.

Unwrap over paper, outdoors. There will be ash, unburnt material and loose salt in there, and none of it is something to shake out over a work table. Peel the foil rather than pulling it, because a torn edge dragged across the surface leaves a scratch you will see forever.

Wipe, do not wash. Start with a dry soft cloth to lift the loose ash, and look at the piece before you decide it needs anything more. If it does, a barely damp cloth and light pressure. What looks like grime on the surface is very often the deepest color on the pot.

Then seal it, because an unsealed saggar surface dulls with handling and slowly loses its edge to light and skin oil. A microcrystalline wax buffed on thin is the usual answer: it deepens the color, evens out the sheen and protects the carbon. An acrylic spray sealer works too and gives a shinier, less natural look.

And know what you have made. Unglazed, low fired, porous, with a surface of carbon and salts. It will not hold water, it is not food safe, and it does not belong in a dishwasher or a microwave. This is decorative work and there is no version of it that is not.

Our kilns are electric and they fire glaze to cone 5½, which is cone 5 with a twelve minute hold. Saggar work is the opposite end of everything: less than half that temperature, a sealed parcel full of salt and copper, and a lot of smoke. Salt and metal vapor are hard on elements and brickwork, and in a shared studio that damage lands on everybody else's firings rather than on yours, which is why this lives outdoors with the raku equipment rather than in the kiln room on Pony Express Road.

So it runs the way our other alternative firings run: as workshops, with a safety meeting in person before anything is lit, a fresh waiver every time, and everybody staying through cleanup. The safety and certification page covers the rules and the choreography, and it is worth reading whether or not you take the card.

Saggar sits alongside the rest of the alternative firing family, and the differences are worth knowing before you pick one. Our raku guide is the overview of all of them. Naked raku builds a shell and takes it off. Horsehair and feather draws on a glowing pot after it leaves the kiln. Saggar is the one where nothing is pulled and nothing is drawn: you build the conditions, close the lid, and find out later.

The clay is the easy part. B-Mix with Grog is on the shelf and takes the temperature swing well while still smoothing up reasonably. Berlin Gray is a dark body, which changes the result completely: your pale areas are not pale, so the piece reads as tone rather than as color. Both are fine choices and they are not the same project.