Overwhelmed with Underglaze
Figuring out what underglaze brand you want is hard. You have to consider how it will look on YOUR clay body? will it uphold in YOUR firings? What are you firing at? Do you like the texture? Is it conducive to how you apply underglaze? And so many more things.
For my purposes, I fire my work at a community studio. We have the option to use a cone 6 clay body, or a cone 10 clay body. For a multitude of reasons, I've chosen cone 10. Therefore, my work is currently fired in a reduction gas kiln at Cone 10. * And often, I use underglaze in my work.
Over the last year I've been testing out different colors and brands as I figure out what underglazes I prefer. I've done a million google searches (if you found this from a google search, welcome!), scrolled through my local community facebook page and a bunch of other ceramic facebook pages and had conversations with many many folks to get a feel of what folks use in Cone 10.**
I've been working primarily with Amaco Velvet underglaze over the last year, and a sprinkling of some Coyote Underglazes. For the most part, I've enjoyed working with these. Purples and vibrant yellow-greens have been difficult to make work - but a majority of colors have held up.
Coyote Underglaze Test Tiles
Lavender MBUG007
Burgundy MBUG027
Pink MBUG011
Blue Pansy MBUG020
Violet MBUG026
Amaco Velvet Underglaze Test Tiles
Bright Orange V-390
Lavender V-320
Light Green V-345
Medium Blue V-326
Terra Cotta V-303
Chartreuse V-343
Jet Black V-361
Salmon V-323
Amethyst V-381
Intense Yellow V-391
Bright Red V-387
White V-360
One of my friends, and a current Artist-in-Residence at the Worcester Center for Craft, Sophie Lever, often uses speedball underglazes. They are a cheaper alternative to Amaco and Coyote, with a more limited palette, but their vibrancy holds up & they work as expected for the most part.(Note: I've been told their purple burns out at cone 10). I've not tested out Speedball for Cone 10, but I've worked with them a decent amount at cone 6. They are straightforward and easy to use. I view them as a very good beginner underglaze - and Sophie's work makes me rethink why I haven't used them in cone 10!
Recently, however, I stumbled upon Western Underglaze. They are a small glaze/underglaze brand based out of California. Their main distributor is Clay Planet, who offers shipping across the USA. They are significantly cheaper than Amaco and Coyote, and when I saw them mentioned in a reddit post, I knew I had to try them. In the reddit post, the photos attached showed insanely vibrant colors coming from these underglazes at Cone 10 reduction (my firing), cone 10 oxidation, and cone 6. I got two teacher sample packs of the underglazes - so 24 colors, 2 oz each - for around $130 with shipping. And let me say, I am super pleased with the results on my test tile!
Of 24 colors only 1 burned out (a purple of course), 4 became quite dark with a satin(in appearance)/metallic surface quality (all darker), and the rest stayed super vibrant - including a really fun green (key-lime) which I'm very excited to use.
Western Underglaze Test Tiles
Silver Gray Ug-3
Redwood Ug-5
Black Ug-1
Royal Blue (New) Ug-19
Light Green Ug-17
Purple (New) Ug-23
Pomegranate Ug-36
Bright Pink (New) Ug-27
Pumpkin Ug-24
White Ug-30
Bright Yellow Ug-12
Sky Blue Ug-21
Medium Gray Ug-2
Ultramarine Blue Ug-18
Golden Yellow UG-9
Dark Green Ug-15
Burnt Orange (New) Ug-8
Violet Ug-40
Guava Ug-28G
Coffee Brown Ug-4
Crimson (new) UG-25
Key lime Ug-38
Mango Red Ug-32
Oasis Teal Ug-39
I'll be using mostly Western on my upcoming project, but may sneak in an amaco or coyote as well. Coyote has the best purple by far (Lavender), while Amaco's Bright Orange and Light Green are great options as well. I'm still on the hunt for the perfect black (catch me scouring the internet again) that doesn't cause any weird reactions with a clear glaze (if you have a suggestion let me know! Jet Black by Amaco tends to produce tiny bubbles while Western is more mattifying and not as black as I'd like). So stay tuned!
My last tidbuit of advice, before layering different brands of underglaze, or a clear coating over a new-to-you underglaze, make sure to do your own test tile! Your clay and glazes might react differently than you hope, and even different brand underglazes can have un-ideal reactions leading to blistering or crawling. So, as I'm sure you know, do your test tiles! (I promise I'll do mine at least 1/3 of the time too)
*“Amanda, I’ve heard the terms Oxidation and Reduction used before - but I don’t realllyyy know what that means…”
Oxidation vs. Reduction refers to how a kiln is fired during a glaze firing.. How a kiln is fired can be dependent on the type of kiln. Electric kilns fire oxidation, whilst gas fire reduction. You might also have heard terms like wood-fire, saggar, raku, salt fire, etc. These are other ways you can fire, and are often more specialized. The kiln’s atmosphere plays a crucial role in how glazes can perform.
Oxidation firings (electric kilns - most studios do cone 6) provide a more controlled, consistent firing with ample oxygen resulting in producing more bright, predictable colors.
Reduction firings (gas kilns - commonly cone 10) on the other hand can have more limited oxygen and are more susceptible to the atmosphere, weather and environment affecting the firings. Reduction firings work by creating an oxygen starved environment with restricted airflow. The lack of oxygen and presence of gases (like carbon monoxide) alters the way metal oxides develop by pulling oxygen molecules directly out of the metal oxides in the clays and glazes. The result is often richer, more varied, complex results with less predictability and deeper, earthier colors. tones and in turn, less predictability.
**If you're not super familiar with the different cones, Cone 10 is fired hotter than Cone 6. This causes different chemical reactions to occur in the materials. For example, if you put a cone 6 clay body in a cone 10 firing, the clay body will melt. In terms of underglazes, this means that sometimes a beautiful underglaze with no issues at cone 6 could fire completely different or burn out all together at Cone 10. I've found this to be especially common in purples and greens.
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