These test were all fired in an electric kiln at the University of Central Florida. Unfortunately, I didn’t keep the firing schedules at this time, and didn’t test with multiple cone packs, however from memory, the kiln that most of these were tested in often under-fired, and as such these may be closer to cone 5 than cone 6.
CO-16-1
Akiko’s Crater Glaze by Akiko Hirai
Cone 6 Oxidation
Silica | 10% |
Nepheline Syenite | 60% |
Barium Carbonate | 18% |
Kaolin | 11% |
Rutile | 2% |
Silicon Carbide | 2% |
A very light in color, matte crater glaze. Not very much cratering, more akin to just a rocky surface. Very stable. Should definitely be applied more thickly. Hirai recommends application over black slip. NOTE
CO-17-1
Marilee’s Lava Glaze (Web)
Cone 6 Oxidation
Whiting | 23.91% |
Custer Feldspar | 49.73% |
EPK | 13.18% |
Silica | 13.18% |
Titanium Dioxide | 11.29% |
Silicon Carbide | 3% |
- A slightly cool hued matte crater, but it seems as though bubbles weren’t able to pop. Ends up bubbly and more pinholed than anything else. Color isn’t very nice. To fix, would need bubble to fully pop (could likely due this either in the glaze chemistry or firing to higher temp).
CO-18-1
Pinnell Strontium Crater (Web)
Cone 6 Oxidation
Nepheline Syenite | 60% |
Strontium Carbonate | 20% |
SIlica | 10% |
Ball Clay | 8% |
Lithium Carbonate | 2% |
Titanium Dioxide | 6% |
Silicon Carbide | 3% |
- Definitely one of the better crater glazes. Nice in color, with a kinda natural off-white into some more glossy areas in color. Appears fairly stable on both stoneware and porcelain. Some bubbles can be popped with pressure, should consider sandblasting or possibly a soaking period.
CO-19-1
Crater Glaze 1255C (Web)
Cone 6 Oxidation
Strontium Carbonate | 15% |
Nepheline Syenite | 61% |
EPK | 11% |
Silica | 13% |
Silicon Carbide | 3% |
- A dark gray crater that’s pretty nice. Many of the bubbles didn’t fully pop, but will pop manually. Would likely be a great candidate for sandblasting. How would soaking effect the popping? This will be a good, simple base to research with.
CO-20-1
Marilee’s Lava (from John Britt’s Mid-Range Glazes)
Cone 6 Oxidation
Custer Feldspar | 49.7% |
Silica | 13.2% |
Whiting | 23.9% |
Kaolin | 13.2% |
Titanium Dioxide | 11.3% |
Silicon Carbide | 3.5% |
Bentonite | 2% |
Don’t especially like the color or surface, but stable on porcelain and stoneware. Bubbles didn’t fully form/pop so looks quite boring. Would need richer surface to enhance.
CO-21-1
Pinnell Strontium Crater (from John Britt’s Mid-Range Glazes)
Cone 6 Oxidation
Nepheline Syenite | 60% |
Silica | 9% |
Ball Clay | 10% |
Strontium Carbonate | 20% |
Lithium Carbonate | 1% |
Titanium Dioxide | 5% |
Silicon Carbide | 5% |
Cobalt Carbonate | 2% |
Bentonite | 2% |
- This one largely failed. The combination of 5% silicon carbide + 2% cobalt resulted in a very dark blue with little actual cratering, and more so small pinholes. Is this the fault of too much silicon carbide or the cobalt? Answer to that: The cobalt carbonate is acting as a flux, causing this texture. To fix, reduce amount of cobalt.
CO-22-1
Jan’s Barium Turquoise
Cone 6 Oxidation
Nepheline Syenite | 60% |
Silica | 10% |
Ball Clay | 8% |
Barium Carbonate | 20% |
Lithium Carbonate | 2% |
Titanium Dioxide | 10% |
Silicon Carbide | 3% |
Copper Carbonate | 0.5% |
Bentonite | 2% |
A very nice surface where the texture can be felt, but isn’t sharp. All of the bubbles seemed to have popped, and the color is quite nice as well. Stable on porcelain and stoneware. On porcelain, tended to thin on edges. Would like to try this without colorants.
CO-23-1
Jan’s Crater C
Cone 6 Oxidation
Custer Feldspar | 37.5% |
F-4 Feldspar | 12.5% |
Silica | 13% |
Whiting | 24% |
Kaolin | 13% |
Rutile | 1.5% |
Titanium Dioxide | 12% |
Silicon Carbide | 3% |
Cobalt Carbonate | 0.5% |
Bentonite | 2% |
This one didn’t even really crater. It’s quite interesting with a purple-ish color and a varied, mottled texture. Very stable, but curious as to why it didn’t fully crater. Perhaps it did, but continued to melt for too long after? (In retrospect, the lower percentages of feldspars fired at cone 6 more likely indicate that the glaze simply didn’t flux enough to crater at cone 6.)
CO-24-1
Jan’s Crater Cover
Cone 6 Oxidation
Custer Feldspar | 25% |
Silica | 25% |
Whiting | 12% |
Kaolin | 25% |
Dolomite | 13% |
Tin Oxide | 3% |
- A very stable semi-matte white. Meant to be used as a base with other glazes, and needs to be tested as such. Looks like paint. Nothing to add until then.
CO-25-1
Chalke Cryolite
Cone 6 Oxidation
Talc | 15% |
Barium Carbonate | 4% |
Cryolite | 75% |
Laguna Borate | 6% |
Chrome Oxide | 1.5% |
Zircopax | 12% |
Bentonite | 2.5% |
Never tested due to studio’s lack of cryolite and its inherent risks.
CO-26-1
Scotchie Textured
Cone 6 Oxidation
Bone Ash | 77.3% |
F-4 Feldspar | 8.6% |
Cryolite | 13.7% |
Barium Carbonate | 0.4% |
Cobalt Carbonate | 1% |
Never tested due to studio’s lack of cryolite and its inherent risks.
CO-27-1
Selsor Red
Cone 6 Oxidation
Nepheline Syenite | 56.3% |
Silica | 20.8% |
Whiting | 10.4% |
Gerstley Borate | 12.5% |
Tin Oxide | 1.5% |
Copper Carbonate | 0.8% |
Bentonite | 2% |
Silicon Carbide (600M) | .8% |
- This glaze was not tested with the recommended 600M silicon carbide, and instead used the silicon carbide present at UCF, which was an unspecified mesh size. Not at all red, but still interesting. More of a hare’s fur. Black with slight hue. Runs a little, could be fixed, but likely wouldn’t be an issue on stoneware. Identical on both stoneware and porcelain.
CO-28-1
John’s Red
Cone 6 Oxidation
Custer Feldspar | 40.2% |
Silica | 25.1% |
Whiting | 8.1% |
Dolomite | 8.3% |
Strontium Carbonate | 4.2% |
Frit 3134 | 12.5% |
Bone Ash | 1.6% |
Silicon Carbide (600M) | 0.8% |
Tin Oxide | 2.5% |
Copper Carbonate | 0.75% |
Bentonite | 2% |
- This glaze was not tested with the recommended 600M silicon carbide, and instead used the silicon carbide present at UCF, which was an unspecified mesh size. Actually a light blue that’s just a bit frothy looking. Still retains some gloss and is actually quite a nice surface. The copper definitely didn’t reduce. Mostly stable on both stoneware and porcelain. Would be interesting to attempt to further increase the gloss.
CO-29-1
Copper Red
Cone 6 Oxidation
Silica | 26% |
Whiting | 1.2% |
Kaolin | 10.5% |
Dolomite | 4.4% |
Frit 3110 | 46% |
Gerstley Borate | 9.9% |
Zinc Oxide | 2% |
Silicon Carbide (600M) | 0.8% |
Tin Oxide | 2% |
Copper Carbonate | 1.5% |
Bentonite | 2% |
- This glaze was not tested with the recommended 600M silicon carbide, and instead used the silicon carbide present at UCF, which was an unspecified mesh size. Not red at all, a kinda frothy grayish with some nice variation. Quite stable. Would like to see on a larger piece. Similar on stoneware and porcelain, stable, but more neutral on porcelain.
CO-30-1
Copper Red Chun
Cone 6 Oxidation
Custer Feldspar | 46.1% |
Silica | 16.5% |
Whiting | 14.3% |
Kaolin | 5.5% |
Frit 3124 | 13.2% |
Zinc Oxide | 4.4% |
Silicon Carbide (600M) | 0.8% |
Tin Oxide | 2% |
Copper Carbonate | 1.1% |
Bentonite | 2% |
- This glaze was not tested with the recommended 600M silicon carbide, and instead used the silicon carbide present at UCF, which was an unspecified mesh size. Extremely puffy and fragile, not red at all. Very light gray. Stable as far as dripping. Maybe add more silicon carbide to convert to crater glaze?
CO-31-1
Daly 1
Cone 6 Oxidation
Custer Feldspar | 28% |
Silica | 21% |
Whiting | 14% |
Kaolin | 7% |
Frit 3124 | 30% |
Silicon Carbide (600M) | 0.8% |
Tin Oxide | 1% |
Copper Carbonate | 1% |
Bentonite | 2% |
- This glaze was not tested with the recommended 600M silicon carbide, and instead used the silicon carbide present at UCF, which was an unspecified mesh size. A puffy grayish glaze. Quite fragile, and not red. Didn’t reduce. Wouldn’t be able to use as is. Fairly stable on both stoneware and porcelain.
CO-32-1
N501
Cone 6 Oxidation
Kaolin | 20% |
Frit 3110 | 80% |
Cobalt Carbonate | 3% |
Bentonite | 2% |
- A flat, glossy dark blue. Quite apparent pinholing, but no crazing. Lighter on porcelain. Could work well as a glossy blue liner glaze.
CO-33-1
Shiny Opal Blue
Cone 6 Oxidation
F-4 Feldspar | 44% |
Silica | 24% |
Whiting | 1% |
Kaolin | 2% |
Barium Carbonate | 6% |
Gerstley Borate | 20% |
Zinc Oxide | 3% |
Cobalt Carbonate | 1% |
Rutile | 4% |
Bentonite | 2% |
A nice, slightly textured middle blue. Some interesting variation and swirls in the texture of it. Slightly runny, more so on porcelain. Would likely need to stiffen a bit. Transparency where thin.
CO-34-1
Opal Blue
Cone 6 Oxidation
Silica | 25% |
Kaolin | 25% |
Frit 3134 | 50% |
Cobalt Carbonate | 1% |
Rutile | 4% |
Bentonite | 2% |
- No idea what happened here. Not very blue and formed almost a cratery texture. Not appealing. Must be the frit? Stable on stoneware and porcelain.
CO-35-1
John’s Cash Blue
Cone 6 Oxidation
Nepheline Syenite | 41.1% |
Silica | 27.7% |
Whiting | 9.4% |
Gerstley Borate | 17.2% |
Lithium Carbonate | 2.9% |
Zinc Oxide | 1.7% |
Cobalt Carbonate | 1% |
Rutile | 4% |
Bentonite | 2% |
- My favorite of these blues, especially on stoneware. A bit transparent, looks like running water. Too fluid on both stoneware and porcelain. Could use as liner as-is, but would need to stiffen otherwise. Porcelain is especially very runny. A bit crazed on porcelain, but not apparent on stoneware.
CO-36-1
John’s Noxzema
Cone 6 Oxidation
F-4 Feldspar | 50% |
Silica | 4% |
Kaolin | 11% |
Strontium Carbonate | 11% |
Frit 3134 | 24% |
Cobalt Carbonate | 3% |
Bentonite | 2% |
- A very flat, but stable blue with some pin holing. Overall, quite boring, but could work as a flat blue with a bit of fixing.
CO-37-1
Blue Spruce
Cone 6 Oxidation
Nepheline Syenite | 25% |
Silica | 15% |
Whiting | 20% |
Kaolin | 15% |
Frit 3124 | 25% |
Cobalt Carbonate | 2% |
Copper Carbonate | 2% |
Rutile | 5% |
Zircopax | 2% |
Bentonite | 2% |
- A very nice green-blue glossy glaze with lots of depth, especially for a mid range oxidation glaze. The color is a dark teal, however it’s speckled with lighter colors, and also lightens where it’s thin, such as the edges. It is a bit runny, and should probably be fixed before production.
CO-38-1
Variegated Slate Blue
Cone 6 Oxidation
Nepheline Syenite | 4% |
Silica | 17% |
Kaolin | 30% |
Wollastonite | 29% |
Frit 3195 | 20% |
Cobalt Carbonate | 1.5% |
Copper Carbonate | 3% |
Rutile | 6% |
Zircopax | 2% |
- A dark greenish teal, glossy, without pin holing or crazing. Very clean on porcelain, but drips too much on porcelain. More variation on stoneware, but almost completely stable. A decent glaze, and would likely look quite sophisticated on fine porcelain.
CO-39-1
Periwinkle
Cone 6 Oxidation
Silica | 26% |
Whiting | 13.3% |
Kaolin | 8.7% |
Magnesium Carbonate | 5% |
Frit 3269 | 42% |
Lithium Carbonate | 5% |
Cobalt Carbonate | 1.5% |
Bentonite | 2% |
Unable to locate tile at time of documentation. Will update if found.
CO-40-1
T2 Bahamas Noxzema
Cone 6 Oxidation
F-4 Feldspar | 76.4% |
Silica | 4.5% |
Whiting | 4.7% |
Dolomite | 6.5% |
Lithium Carbonate | 3.8% |
Zinc Oxide | 4.1% |
Cobalt Carbonate | 2.5% |
Bentonite | 2% |
- A glossy blue with a decent bit of transparency as shown by the difference on stoneware vs. porcelain. Gets darker where glaze is thicker. Some light pinholing. Overall a decent glaze, but nothing very special.
CO-41-1
Mary Cay Lapis
Cone 6 Oxidation
G-200 Feldspar | 44% |
Silica | 11% |
Kaolin | 11% |
Dolomite | 12% |
Gerstley Borate | 11% |
Zinc Oxide | 11% |
Cobalt Carbonate | 4% |
Bentonite | 2% |
- A very dark blue, slightly lighter on porcelain due to a bit of transparency. Runny, but no pin holing or crazing, so could likely fix by just adding a bit of kaolin. Could use as a liner as is.
CO-42-1
Basic (Amber Celadon)
Cone 6 Oxidation
Custer Feldspar | 25% |
Silica | 25% |
Whiting | 25% |
Ball Clay | 25% |
Red Iron Oxide | 3% |
Bentonite | 2% |
- A semi-transparent and glossy (but not too glossy) amber glaze. A pretty earthy brown/orange, but the transparency makes it alright on porcelain, and it may be to the liking of some on stoneware. There doesn’t appear to be any pin holing or crazing, and it’s stable, so if it’s to your liking, it would be suitable for all uses.
CO-43-1
Korean (Amber Celadon)
Cone 6 Oxidation
Custer Feldspar | 25.6% |
Silica | 20.6% |
Whiting | 25.6% |
Kaolin | 6.9% |
Ball Clay | 20.6% |
Bone Ash | 0.7% |
Red Iron Oxide | 1.5% |
Yellow Ochre | 2% |
Bentonite | 2% |
- A pleasingly pale semi-matte amber. There’s some light crazing on porcelain, but no issues with crazing, pin holing, or runniness on stoneware. Definitely some potential here, and would be ready for usage.
CO-44-1
Conan Amber
Cone 6 Oxidation
Custer Feldspar | 44% |
Silica | 12.8% |
Whiting | 17.7% |
Ball Clay | 6.1% |
Redart Clay | 11.1% |
Talc | 3.8% |
Gerstley Borate | 2.5% |
Bone Ash | 2% |
Red Iron Oxide | 4.1% |
Bentonite | 2% |
A dark, glossy amber with lots of pin holing and some crazing, but stable. The color is a nice dark brown, and the transparency is nice, however the pin holing make the surface quite ugly. If this was fixed, then it may be a good candidate for usage.
CO-45-1
John’s Amber
Cone 6 Oxidation
Nepheline Syenite | 24.2% |
Silica | 18.2% |
Whiting | 23.2% |
Kaolin | 20.1% |
Frit 3134 | 8.1% |
Lithium Carbonate | 6.2% |
Red Iron Oxide | 5% |
Bentonite | 2% |
A sub par amber with a lot of transparency, runniness, and almost looks like a wash on stoneware. Too many issues here to warrant further testing.
CO-46-1
Amber 1
Cone 6 Oxidation
Custer Feldspar | 24.3% |
Silica | 18.7% |
Whiting | 24.3% |
Kaolin | 6.5% |
Ball Clay | 18.7% |
Lithium Carbonate | 7.5% |
Yellow Ochre | 9.4% |
Bentonite | 2% |
- A greatly transparent amber - though the color is nice, but with issues in crazing and runniness, especially on porcelain. This would require some significant work to fix, and the 7.5% lithium make this a bit impractical - however the removal of this may actually fix the runniness. Overall decent, but nothing to warrant further usage or testing.
CO-47-1
Amber 2
Cone 6 Oxidation
Nepheline Syenite | 18% |
Silica | 10% |
Whiting | 15% |
Wollastonite | 9% |
Kaolin | 3% |
Redart Clay | 39% |
Frit 3134 | 4% |
Bentonite | 2% |
- A semi-matte amber with a pig skin texture due to pin holing and some crazing issues on porcelain. The color is a medium earthy orange, however the overall appearance of this glaze just isn’t to my satisfaction.
CO-48-1
New Tyler Amber
Cone 6 Oxidation
Redart Clay | 60% |
Frit 3110 | 20% |
Gerstley Borate | 20% |
Bentonite | 2% |
- Probably my favorite of the ambers here - very dark in color with high glossiness, and transparency where it runs thin (edges etc.). There may be very slight pin holing, however this is a fairly insignificant amount. As a dark amber, this glaze would be wonderful, however the usage of redart to produce the color make lightening this glaze a larger issue than it would be to simply reduce the amount of an oxide.
CO-49-1
Steve’s Amber
Cone 6 Oxidation
Nepheline Syenite | 17% |
Silica | 18% |
Whiting | 4% |
Wollastonite | 13% |
Ball Clay | 3% |
Alberta Slip | 30% |
Gerstley Borate | 15% |
Yellow Ochre | 7% |
Bentonite | 2% |
A pretty transparent, glossy, amber glaze with a little bit of pin holing on stoneware, and some significant crazing on porcelain. Very runny on both tiles, and where it accumulates there’s actually a lot of depth and even some speckling of blue. Would need to be more stable for use.
CO-50-1
Amber Temmoku
Cone 6 Oxidation
Custer Feldspar | 70% |
Silica | 5% |
Whiting | 5% |
Frit 3110 | 20% |
Red Iron Oxide | 5% |
Bentonite | 2% |
A glossy, but fully opaque amber. Not the prettiest color - kind’ve a brownish, dull orange, with a lot of crazing and a pig skin like texture from pinholes. It is stable though. Doesn’t warrant any further testing from me.
CO-51-1
V.C. 71 Satin Matte
Cone 6 Oxidation
Custer Feldspar | 40% |
Silica | 16% |
Whiting | 16% |
Kaolin | 10% |
Talc | 9% |
Frit 3124 | 9% |
Bentonite | 2% |
- A milky sort of semi-matte. No crazing, but possibly very, very minor pin holing. A good deal of transparency. A decent matte base, and could possibly used as a base for further testing. Stable on stoneware.
CO-52-1
V.C. 72
Cone 6 Oxidation
Nepheline Syenite | 24% |
Silica | 40% |
Whiting | 4% |
Kaolin | 7% |
Dolomite | 11% |
Gerstley Borate | 12% |
Zinc Oxide | 2% |
Bentonite | 2% |
- A decent clear, without crazing or pin holing, and stable, but it is a bit cloudy.
CO-53-1
Semi-Matte
Cone 6 Oxidation
Nepheline Syenite | 33.9% |
Silica | 15.9% |
Whiting | 3.5% |
Kaolin | 20.3% |
Dolomite | 17.6% |
Gerstley Borate | 8.8% |
Bentonite | 2% |
Unable to locate tile at time of documentation. Will update if found.
CO-54-1
Eggshell Matte
Cone 6 Oxidation
Custer Feldspar | 47% |
Whiting | 14% |
Kaolin | 19% |
Dolomite | 10% |
Gerstley Borate | 10% |
Bentonite | 2% |
- Egg shell matte is a very apt name for this, as it’s pretty close to that texture. Some speckling that adds a bit of interest to a matte white glaze. No pin holing or crazing, making this a pretty great base.
CO-55-1
Matte White
Cone 6 Oxidation
Custer Feldspar | 47% |
Kaolin | 20% |
Ball Clay | 6% |
Dolomite | 28% |
Frit 3134 | 2% |
Bone Ash | 5% |
Bentonite | 2% |
This is the exact texture that I was looking for and very stable. I want to run tests with this as the base.
Colorant TestsCO-56-1
Autumn’s Crystal Matte
Cone 6 Oxidation
F-4 Feldspar | 34.4% |
Silica | 12.3% |
Whiting | 10.7% |
Kaolin | 4.8% |
Talc | 24.6% |
Frit 3134 | 9.9% |
Zinc Oxide | 3.3% |
Tin Oxide | 1.7% |
Bentonite | 2% |
Unable to locate tile at time of documentation. Will update if found.
CO-57-1
Pike’s Oatmeal
Cone 6 Oxidation
F-4 Feldspar | 37.4% |
Silica | 22.7% |
Kaolin | 4.5% |
Dolomite | 6.4% |
Talc | 13.6% |
Gerstley Borate | 12.7% |
Zinc Oxide | 2.7% |
Bentonite | 2% |
Unable to locate tile at time of documentation. Will update if found.
CO-58-1
Lalone Crawl
Cone 6 Oxidation
Nepheline Syenite | 70% |
Ball Clay | 5% |
Magnesium Carbonate | 25% |
Bentonite | 2% |
- A pretty great glossy, globby crawl, without much dripping. Chunks up a good amount. Would be a good candidate for testing with some stains.
CO-59-1
Lichen
Cone 6 Oxidation
F-4 Feldspar | 30% |
Kaolin | 19% |
Magnesium Carbonate | 31% |
Talc | 8% |
Frit 3134 | 6% |
Zinc Oxide | 6% |
Another one of my favorite crawls. It’s matte and has a great density. Another candidate for testing with stains and oxides.
CO-60-1
Magnesium Matte 6
Cone 6 Oxidation
Nepheline Syenite | 43.5% |
Silica | 8.7% |
Whiting | 21.7% |
Kaolin | 8.7% |
Magnesium Carbonate | 17.4% |
- It’s a very nice surface, and crawls where it’s a bit thin. This could be viewed as a matte base where a reduction in magnesium could result in a very nice matte glaze, on you could increase magnesium for a stronger crawl. Alternatively, it could be interesting to apply super thinly. There doesn’t appear to be any issues with crazing or pin holing.
CO-61-1
High Calcium Semi-Matte
Cone 6 Oxidation
Nepheline Syenite | 4% |
Silica | 17% |
Wollastonite | 29% |
Kaolin | 30% |
Frit 3195 | 20% |
Bentonite | 2% |
- A decent clear but some cloudiness. Wouldn’t use for this reason.
CO-62-1
Easy E Clear
Cone 6 Oxidation
Nepheline Syenite | 20% |
Silica | 25% |
Wollastonite | 20% |
Kaolin | 15% |
Frit 3124 | 20% |
Bentonite | 2% |
The best cone 6 clear that I’ve tested. Seems to be fine, thick or thin. No crazing, no dripping, no pin holing, and no dripping.
CO-63-1
Hadi’s Black Slip
Cone 6 Oxidation
Ball Clay | 25% |
EPK | 25% |
Calcined Kaolin | 25% |
Barnard Slip | 25% |
Custer Feldspar | 10% |
[Unable to find tile to photograph]
Crawled/cracked a ton. Not a real black, more of a dark brown/red. It is somewhat interesting, but should be tried on greenware instead of bisque as shown here.
CO-64-1
Dolomite Crater
Cone 6 Oxidation
Nepheline Syenite | 60% |
Silica | 10% |
Ball Clay | 8% |
Dolomite | 20% |
Lithium Carbonate | 2% |
Silicon Carbide | 3% |
Bentonite | 2% |
[Unable to find tile to photograph]
Kinda soapy but not the right texture.
CO-65-1
Albany Black
Cone 6 Oxidation
Albany/Alberta Slip | 63.2% |
Cornwall Stone | 15.8% |
Whiting | 10.5% |
Gerstley Borate | 10.5% |
Cobalt Carbonate | 1% |
Red Iron Oxide | 9% |
- A slip-based black that separated into matte and glossy - an interesting look. Too drippy to be useful, and not enough interest to promote further research.
CO-66-1
Albany Black 1
Cone 6 Oxidation
Albany/Alberta Slip | 75% |
Nepheline Syenite | 20% |
Gerstley Borate | 5% |
Cobalt Oxide | 2% |
- A pinhole filled, almost lumpy sorta black. Glossy. Not interesting.
CO-67-1
Barnard Slip
Cone 6 Oxidation
Barnard Slip | 100 |
- A matte, black, cracked glaze, but was applied to bisqueware rather than greenware, so this may be responsible. Still pretty interesting, as the glaze is quite thick and the cracks reveal this cross section.
CO-68-1
Frost Black Satin Matte
Cone 6 Oxidation
Nepheline Syenite | 31.8% |
Silica | 22.7% |
Whiting | 22.7% |
Ball Clay | 13.6% |
Zinc Oxide | 9.2% |
Black Iron Oxide | 4.3% |
Manganese Dioxide | 1.8% |
Cobalt Oxide | 3% |
Copper Oxide | 1.8% |
Bentonite | 2% |
Unable to locate tile at time of documentation. Will update if found.
CO-69-1
Scotchie Textured
Cone 6 Oxidation
Bone Ash | 77.3% |
F-4 Feldspar | 8.6% |
Cryolite | 13.7% |
Barium Carbonate | 0.4% |
Cobalt Carbonate | 1% |
Never actually tested.
CO-70-1
Suze’s Black Slip
Cone 6 Oxidation
Alberta Slip | 72% |
Ball Clay | 18% |
Chrome Oxide | 7% |
Cobalt Oxide | 1.5% |
Red Iron Oxide | 1.5% |
- A kinda metallic black, with smaller cracks. This was applied to bique rather than greenware. Somewhat interesting, and should probably test with greenware. Could possibly sub cobalt oxide for 2.25% cobalt carbonate.
CO-71-1
Ballingham Black Slip
Cone 6 Oxidation
Silica | 33.5% |
Minspar 200 | 22.5% |
EPK | 22% |
OM4 Ball Clay | 22% |
Manganese Dioxide | 10% |
Red Iron Oxide | 10% |
Chrome Oxide | 5.5% |
Cobalt Oxide | 2% |
- A cracked matte black. There’s definitely some interest here, but it isn’t the smooth black slip that I expected. This was applied to bisqueware instead of leather hard though, so this may be the issue. This cracking could be viewed as a decorative feature of a black glaze as well.
CO-18 Strontium Crater Colorant Tests
CO-22 Barium Crater Colorant Tests
Both of the above can be found in The History of Crater Glazes book on this website.