Verdict
Mayco Stoneware glazes are one of the easiest ways to get reactive, studio-style surfaces from a cone 6 electric kiln. The line spans Classic, Matte, Crystal and Gloss glazes, all rated cone 5/6 to 10, with chips fired at cone 6 in oxidation and cone 10 in reduction on white stoneware. They brush on from a pint, and many colors are also sold as 10 lb dry bags for dipping.
Labels are the thing to watch. Most of the colors we checked carry Mayco's dinnerware safe icon, but SW-132 Mirror Black is not recommended for dinnerware, and Mayco warns that it, and the crystal glazes, can move. This review is research-based, built from Mayco's product pages and safety pages in October 2026; we did not fire these glazes ourselves.
The line at a glance
| Surface | Examples | Cone (Mayco) | Sizes | Dinnerware label |
|---|---|---|---|---|
| Satin, matte and iron | SW-104 Black Walnut, SW-122 Maycoshino, SW-129 Copper Float | 5/6 to 10 | Pint; 10 lb dry (SD codes) | Dinnerware safe (these three) |
| Crystal | SW-156 Galaxy, SW-116 Robin's Egg | 5/6 to 10 | Pint; Galaxy also 10 lb dry | Dinnerware safe (these two) |
| Metallic gloss | SW-132 Mirror Black | 5/6 to 10 | Pint; 10 lb dry | Not recommended for dinnerware |
| Clears | SW-001, SW-002, SW-003, SW-004 | 5/6 to 10 (SW-004 rated cone 6) | Pint, gallon, 10 lb dry | SW-001, 002, 004 safe; SW-003 decorative |
| Specialty | Magma, Mudcrack, Crackle White | 5/6 to 10 | Varies | Decorative only |
| Flux | SW-401 Light Flux, SW-402 Dark Flux | 5/6 to 10 | Varies | Check each |
Mayco also sells Stoneware Engobes for changing the clay surface color on wet clay, greenware or bisque. Codes in the main range start at SW-100 Blue Surf and run past SW-190.
Mayco glazes for cone 6
Searchers looking for Mayco glazes at cone 6 usually have a home electric kiln, and this is the line made for it. Mayco shows every Stoneware color at cone 6 oxidation as its main chip, and most product pages also list cone 5. Two other Mayco lines reach cone 6: Stroke & Coat, which Mayco rates cone 06 to 10 (see our Stroke & Coat review), and Fundamentals underglazes under a clear. Low-fire lines such as Elements and Jungle Gems can change and run at cone 6, so they are not a substitute.
Standout colors, from Mayco's data
SW-104 Black Walnut
Black Walnut is picked because it shows how much coat count changes a Stoneware glaze. Mayco describes a dark brown soft matte that breaks warm brown at cone 6, with richer brown undertones at cone 10. Thin coats fire lighter brown; Mayco suggests four or more coats for a saturated, opaque finish. It also appears in Mayco's layering samples with SW-401 Light Flux and SW-402 Dark Flux. A deeper page is planned at Mayco Black Walnut.
- Finish: satin matte
- Cone: 5, 6 and 10; oxidation or reduction
- Coats: 4+ for saturated color
- Sizes: SW-104 pint; SD-104 10 lb dry
- Label: ACMI seal; dinnerware safe
Pros
- Rich brown that shows texture
- Dinnerware label
- Dry option
Cons
- Needs many coats for full color
- Wood and soda results vary per Mayco
Who should skip it: potters who want a bright or glossy color.
SW-129 Copper Float
Copper Float is picked for its range in one jar. Mayco describes hues from reds to coppers to gunmetal blacks, mainly a dark rusty red with a satin matte surface at cone 5 to 6. One coat looks dark and greenish, two to three coats deepen it, and thicker coats turn metallic red. At cone 10, Mayco says the finish flattens to a warm brown with copper mottling.
- Finish: satin matte at cone 5 to 6
- Coats: 1 for greenish tones; 2 to 3 for depth; thicker for metallic red
- Sizes: SW-129 pint; SD-129 10 lb dry
- Label: ACMI seal; dinnerware safe
Pros
- Many effects from one glaze
- Breaks over texture
Cons
- Results swing with thickness, so test tiles are a must
Who should skip it: anyone who needs matching color across a set of plates.
SW-122 Maycoshino
Maycoshino is picked as a variegating iron glaze in the style of traditional Shino. Mayco's coat guide is unusually clear: one coat gives a solid reddish brown, two coats give a cream to tan finish that breaks brown over texture, and three coats give waves of cream over the reddish base. At cone 10 reduction it darkens to gray brown.
- Type: variegating iron glaze
- Coats: 1 brown; 2 cream-tan; 3 cream waves
- Sizes: SW-122 pint; SD-122 10 lb dry
- Label: ACMI seal; dinnerware safe
Pros
- Predictable coat-by-coat effects
- Works on any clay per Mayco
Cons
- Earthy palette only
Who should skip it: potters after bright blues and greens.
SW-156 Galaxy
Galaxy is picked as the best-documented crystal glaze in the line. Mayco describes a semi-transparent charcoal gloss with white, orange and blue crystals that bloom at cone 6 and turn bluer and melt at cone 10. The crystals settle in the jar, so stir well before use and between coats. Mayco says to keep crystals off the bottom third of vertical pieces, because over-application can cause pinholing or running. For a lighter crystal effect, Mayco suggests two coats of SW-209 Charcoal, the base glaze, with one coat of Galaxy on top.
- Finish: gloss with three-tone crystals
- Cone: 6 oxidation; 10 reduction (crystals melt)
- Sizes: SW-156 pint; SD-156 10 lb dry
- Label: ACMI seal; dinnerware safe
Pros
- Striking crystal bloom
- Clear placement advice from Mayco
Cons
- Crystals can run or pinhole if heavy
- Needs stirring between coats
Who should skip it: beginners glazing tall forms who do not want to manage placement.
SW-004 Zinc-Free Clear
Zinc-Free Clear is picked because many potters put underglaze greens under a clear at cone 6, and Mayco designed SW-004 for glazes and underglazes with chrome-based pigments. Mayco lists Fundamentals UG-21 Leaf Green, UG-22 Spring Green and UG-210 Forest Green among the colors it suits. It fires to a brilliant, smooth clear at cone 6 with no change at cone 10, but Mayco warns it may cloud if applied too thick. Our planned zinc free clear glaze page goes further.
- Cone: 6 oxidation; no change at 10 reduction
- Sizes: SW-004 pint and gallon; SD-004 10 lb dry
- Label: ACMI seal; dinnerware safe
Pros
- Keeps chrome greens from shifting
- Liquid or dry
Cons
- Clouds when thick
Who should skip it: potters with no chrome-green colors, who can use SW-001 Stoneware Clear.
Not every Stoneware glaze is for dinnerware. Mayco says SW-132 Mirror Black is not recommended for dinnerware and "WILL move," and its Magma, Mudcrack, Crackle White and Crackle Matte Clear glazes are decorative only. Check the icon on each product page.
Can you layer Mayco Stoneware glazes?
Yes, layering is one of the main reasons potters buy this line. Mayco's combination samples were made by brushing two coats of the base glaze, then two coats of the top glaze, letting each coat dry. The combination is written as "top glaze over base glaze." Mayco fires its cone 6 combinations in oxidation and its cone 10 combinations in reduction, both on white stoneware, and says testing is suggested because clay, thickness and firing all change the result.
- Four coats total is a thick layer, so keep layered glaze off the bottom third of tall pieces.
- Crystal tops such as Galaxy or SW-116 Robin's Egg are designed to go over their own base (SW-209 Charcoal and SW-105 Frost Blue respectively, per Mayco).
- Flux glazes (SW-401 and SW-402) are layering products that add movement; test them on a tile with a catch tray or cookie of clay underneath.
The same principles apply to other brands; see AMACO glaze layering for that line's rules.
Pints or dry?
Pints are ready to brush and suit home potters glazing a few pieces per firing. The 10 lb dry bags (SD codes) are for dipping buckets: you mix the powder with water, sieve it and adjust it to a dipping consistency. Dry mix costs less per pot in volume, but Mayco's safety sheet says mixing dry glaze should not be done without a NIOSH-approved respirator because of silica dust. Our planned guide on mixing glaze from powder covers the process.
What Mayco Stoneware does well
- Clear per-color data: coat counts, cone 6 and 10 notes and dinnerware icons on each product page.
- Reactive surfaces at cone 6: breaking, variegated and crystal effects in an electric kiln.
- Liquid or dry: start with pints, move to dry buckets for favorites.
- Matching clears: four clears designed for the line.
Weak points
- Movement: gloss and crystal colors can run; Mayco warns about Mirror Black and crystal placement.
- Coat sensitivity: Copper Float and Maycoshino look very different at one, two and three coats.
- Some decorative-only colors sit in the same line as dinnerware-safe ones.
- Wood and soda results vary, as Mayco notes on several pages.
Who should buy and who should skip
Buy them if you fire at cone 5 to 6 in an electric kiln, want studio-style reactive glazes without mixing recipes, and are willing to fire test tiles.
Skip them if you fire low fire only (choose other Mayco lines), want perfectly even flat color (Stroke & Coat is easier), or mix your own glazes from raw materials.
Alternatives
AMACO Potter's Choice is the closest rival at cone 5 to 6; see Potter's Choice glazes and our AMACO glazes review. For general background on cones, labels and buying glaze, start at the clay and glazes hub, and for application, read how to glaze pottery.
Sources: Mayco Stoneware, Stoneware Clear and Stoneware Specialty line pages; Mayco product pages SW-104 Black Walnut, SW-116 Robin's Egg, SW-122 Maycoshino, SW-129 Copper Float, SW-132 Mirror Black, SW-156 Galaxy, SW-001 Stoneware Clear, SW-004 Zinc-Free Clear; Mayco glaze combinations page; Mayco Dinnerware Suitability and ACMI page; Mayco Consumer Product Information Sheet. Specs checked October 2026.