Studio Glazes
Our glazes are in a constant state of flux at the studio. We regularly introduce new glazes to give our students fresh colors and textures to explore. You can check out our food safety information here. You can also find information on basic glazing practices on our student info page. This is our current lineup:
Wanamaker
Wanamaker is a matte, turquoise glaze with many faces. On any clay it will show three different colors depending on thickness. When thin it is a pale green, but as it thickens it moves to a charcoal green and then eventually pools bright turquoise when thick enough. It is a challenging glaze that doesn't play particularly well with other glazes. If you operate within the glaze's strengths though, you can achieve great results. It is an excellent choice for showing off texture and adding a bit of spontaneity to a pot. Be careful when glazing, drips will definitely show with this glaze. Food safety rating: 2
Umoja
Umoja brings the funk. Just like Wanamaker, this glaze has many faces. While it appears matte on its own, beware because it will make most glazes it mixes with go glossy and run wild! This glaze is loaded with all the good stuff: copper, zinc, lithium, titanium and soda ash. By itself on white clays it produces brilliant colors and effects. When mixed with a more neutral, gloss glaze, the copper, titanium and lithium really come through. You can get streaks of white, blue and bright green. Use this glaze carefully, our kiln shelves are quite familiar with it at this point. Food safety rating: 4
Along with being the Swahili word for "unity", Umoja is a fertile, green planet in the Koprulu sector of the Starcraft universe.
Soft White
Good studio glaze lineups have a balance of adventurous and stable glazes. Soft white is an anchor glaze here. By itself, it has a lovely, semi-matte (depending on the clay) finish that shows off clay speckles and bright underglazes. It mixes well with practically every other glaze and is a great choice for beginners. It is forgiving and safe. Use it in combination with our brown clays and dark glazes to create contrast and interest. It is completely food safe, and will hold up well over time. Food safety rating: 1
Mara Sara
Of all the glazes I've come up with at the studio, I am most proud of Mar Sara. It is a a kaki-red glaze adapted from a John Britt straw ash recipe. It has a semi-matte finish and does spectacular things when mixed with other glazes. Despite being full of colorants, the glaze is food safe and well balanced. You can achieve bright, tomato reds on brown clay and crystalline deposits on porcelain. Pay attention to glaze thickness when using Mar Sara as it can run quite a bit when combined with other drippy glazes. Food safety rating: 2
Although often confused in our studio with the south Asian spice genre "Masala", Mar Sara is a fiery, mining planet located in the outer colonies of the Starcraft universe.
Gloss Black
Another anchor glaze at the studio. Gloss black is a rich, saturated glaze that plays well with the rest of the lineup. It is stable and predictable. You can see some nice, silver crystals that show through on our speckled stoneware clay. When mixed with another color-rich glaze you can get mottled, hare's fur patterns. Although this glaze gets a full melt in the kiln, it is not runny and is an excellent choice for beginners. Food safety rating: 2
Egg
Our adaptation for a cone 6, electric shino. Egg is a wonderfully balanced and stable glaze. It brings the best out of our other glazes and is very versatile. It pools a creamy white, and breaks an iron, orange. Use this glaze to show off texture and add interest to a glaze that might otherwise be flat. Egg has an organic, comforting look and gives pots a lasting presence. This glaze is great for beginners, advanced potters and everyone in between. Food safety rating: 1
If you see "egg" in a glaze name, it's usually because of the glaze's eggshell finish. Our glaze however, looks like a fried egg. Fried eggs are beautiful.
Clear
We have the best cone 6 clear glaze in the biz. I've tested and modified dozens of clear glaze recipes and this is the best. It fits all four of our cone 6 clays, melts well, does not pinhole and does not turn cloudy when it pools. It is forgiving when thin and thick. Use clear to dilute other color saturated glazes or to show off underglazes and raw clay. Food safety rating: 1
Psionic Celedon
Psionic Celedon is meant to capture the cool, gray, blue-green hue that an iron celedon achieves in reduction. It is a subtle glaze that will grow on you over time. Psionic Celedon is stable and forgiving. The surface is glossy and smooth while not moving much in the kiln. Would you guess that four different oxides are involved in producing this simple green? Food safety: 1
Protoss are masters of manipulating psionic powers which usually manifest on the battlefield in the form of blue and green energy.
Zerg
For those interested in drippy, bright colors, Zerg is for you. This glaze is not especially predictable, but it does produce brilliant colors when used correctly. Zerg goes from pink/brown, to dark purple, to bright/white purple as it gets thicker. Use Zerg to highlight sections of your pot. If covering your whole pot in Zerg, make sure you have a beefy foot with plenty of clearance in anticipation of drips. Zerg will surprise you with all colors of the rainbow when paired with the right glaze. Food safety rating: 4
Zerg are a menace to the universe. Governed only by their Overmind, they will overrun anything in the name of The Swarm. Although repulsive to look at, their skins and carapaces' share a similar color with our glaze.
Nerazim
In one sense, Nerazim is the product of a glaze that I spent over a year chasing. I was after a copper blue. About one hundred test tiles later, I decided that some of the shades I was getting in between green and blue were beautiful. Nerazim stood out among the pack.
It is a strongly alkaline base glaze with no clay and a lot of glass. A scoop of titanium, copper and lithium with some tin on top. Enjoy. Food safety rating: 2
The Nerazim are faction of Protoss that have separated themselves from the Khala(which most Protoss derive their energy from). They use a verdant green as their tribal color. Nerazim can often be identified by their glowing, green eyes.
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Glacius
I finally got up the nerve to retire Indigo Float at the studio. Luckily, I've replaced it with a remarkably similar floating, blue glaze. Glacius mixes incredibly well with the rest of the studio glazes. The blue will come through in most pairings, but in slightly different shades. It has some oil-spotting and hares-fur tendencies when mixed with the right counter part.
Cobalt and rutile tend to degas at the wrong time in the kiln which makes floating blues prone to pin-holing. To combat this, Glacius is made from a base glaze of all the best melters. Very frit heavy. Food safety: 3
Glacius is an oceanic planet on which the Protoss established a robust research facility operated by the Khalai caste.
Leviathan
After three full, 5-gallon buckets of studio scrap glaze accumulated I began testing to create a worthwhile mystery glaze. So was Leviathan born.
The scrap glaze started as a bland pink. I stabilized the surface and moved the color closer to a purple with the addition of cobalt and talc. It is a fun glaze that breaks dramatically while moving between gloss and matte textures. When paired with the right studio glaze, you can achieve bright purples. Food safety: 4
The Leviathan is a floating, apex abomination of the Zerg race. The studio scrap glaze is a monster in my mind so it is a fitting name. It's also not a bad approximation of what the fleshy carapace of the purple Leviathan may be like. Combine with other studio glazes to get less of a monster skin look.
Artanis
Artanis is the crown jewel of our scrap glaze recipes. Though Artanis doesn't have a specific recipe, we have a known group of material additives that reliably create Artanis from the studio scrap glaze bucket. This does mean that there is variation in how Artanis looks month to month and studio to studio. The overall look and feel though is consistent. It's an earthy, matte blue with great texture and breaking qualities. Food safety: 3
Artanis is the leader of the Daelaam, protégé of Tassadar, and unifier of the fractured Protoss.
Glaze Food Safety
Each glaze at Indigo Fire is given a food safety rating of 1-5, 1 being the most food safe. The food safety rating is just a suggestion and not based on any proven toxicity with our glazes. In fact, oppositely, we've never had an instance of our glazes breaking down over time besides mild crazing in heavily use mugs which nearly always occurs. We don't send our glazes to a lab to get durability tested because we are always adjusting the recipes slightly, and a food safety rating is nullified when glazes are mixed. We don't use any lead, barium, or cadmium in our glazes. There are small amounts of materials like copper and cobalt however. So with this all in mind, our food safety rating is based on three main criteria:
1) Are there heavy metals with known toxicity in the glaze recipe
2) Is the glaze surface well melted
3) Are there significant glaze defects
So what rating is actually safe for functional tableware? Sadly there's no definitive answer. If you're selling functional pottery, there is perhaps a stronger assumption that the ware is known to be completely food safe. If you're making pots for yourself or a friend, it's a judgement call. You can use the same criteria listed above to decide for yourself. If a glaze satisfies the 2nd and 3rd criteria, you likely don't have to worry about whether or not there are heavy metals in the recipe.
It's also important to remember that the potential leaching of toxic glaze materials is something that would occur over a long period of time. Many many cycles through the dishwasher, microwave and oven are the type of thing that would degrade a weak glaze. We are exposed to trace amounts of heavy metals when working with glaze in the pottery studio and in our day to day lives. Our bodies naturally use small amounts of copper, cobalt, iron, lithium etc in normal functioning. Reducing exposure is certainly prudent though and everyone should assess their own risk. For practical purposes (given the glaze materials we work with), glaze food safety is something to be mindful of over time, but not to fear.