Verdict
Spectrum is a strong pick if you fire to cone 5 or 6 and like reactive, layered surfaces. Its 1430 Floating glazes give a two-tone look from one jar, its 1500 Nova and 1420 Ash lines were built for layering, and the 1100 series offers more than 80 mid-range colors. Low fire potters get just as many options.
The weak spot is information. Spectrum's website lists names and sizes but very little application guidance, its color charts use icons for food labels that are easy to miss, and cone labels differ between the site menu, charts and price list. You will lean on dealers and test tiles more than with AMACO or Mayco. This review is research-based, built from Spectrum's site, color charts and 2026 price lists in October 2026; we did not fire these glazes ourselves.
Spectrum glaze lines at a glance
| Series | What it is | Cone (Spectrum) | Food label (chart header) |
|---|---|---|---|
| 1100 | Mid-range stoneware: gloss, satin, textured, running and reactive | 4/6 on site; chart says cone 5; price list cone 5/6 | Mixed; check each color's icon |
| 1430 Floating | One-jar, two-tone floating glazes | 4/6 on site; price list cone 5/6 | Read each label |
| 1500 Nova | Layering stoneware glazes, brushing and dipping | 4 to 6 | "Dinnerware safe" with exceptions |
| 1420 Ash | Six ash-look layering glazes | 4 to 6 | "Dinnerware safe" with exceptions |
| 1400 Shino | Shino glazes for electric firing | Chart says cone 5; site 4/6 | Not stated on chart |
| 1460 | Semi-transparent, celadon-style | 4 to 6 | "Dinnerware safe" with exceptions |
| 1200 | High fire glazes | Site says 9/10; chart says 8/10 | "Dinnerware safe" with exceptions |
| 700, 800, 900, 250 | Low fire gloss, semi-transparent, Low Stone and satin | 06/04 | Mostly dinnerware safe; exceptions listed |
| 500 and 5500 | Underglazes and One-Stroke concentrated underglazes | 06 to 6 | Dinnerware safe under a clear |
Spectrum's own sources disagree on some cones. The 1100 series is "Cone 4/6" in the site menu, "CONE 5" on its color chart and "Cone 5/6" on the 2026 price list. The 1200 series is "Cone 9/10" on the site and "Cone 8/10" on its chart. Treat cone 5 to 6 as the safe target for the stoneware lines and fire a test tile at your own cone.
Mid-range Spectrum glazes (cone 4 to 6)
1100 series stoneware
The 1100 series is Spectrum's main cone 5/6 line, with 84 listings on its site. It runs from gloss basics such as 1100 Transparent, 1107 Black and 1118 White, through satins (1120 Satin Clear, 1121 Satin White) and "Text." textured glazes, to "Run." running glazes and reactive colors. Spectrum's older product guide says reactive chips were shown at three brush coats fired to cone 5, and that dry 10 lb bags are for dipping. Some popular 1100 glazes have their own pages here: Spectrum Gold, Spectrum Mirror and Spectrum Moonscape.
1430 Floating glazes
Floating glazes are named for how they look: a top color that seems to float over a second color, from a single jar. The site lists 25 colors, including 1431 Pearl White through 1454 Tapenade, sold by the pint, gallon and 10 lb dry. Our Spectrum Floating glazes guide covers the series, and several colors have their own pages, including Sangria, Pearl White, Cactus, Shallot, Sunrise and Tiger Eye.
1500 Nova and 1420 Ash
Spectrum's chart heads these lines "Nova and Ash Layering Glazes," marked lead free and dinnerware safe at cone 4 to 6, with some exceptions. Nova comes as a brushing series and a dipping series (32 colors each on the site). The six Ash glazes are made to pair with 1100 colors, which is where Spectrum's published combinations come from.
1400 Shino and 1460 Semi-Transparent
The 1400 Shinos are cone 5 shino-style glazes for electric kilns, 14 colors on the site. The 1460 series is a set of faux-celadon, semi-transparent glazes such as 1466 Celadon and Rainy Day, made to pool in texture.
Spectrum glaze combinations Spectrum publishes
Spectrum does not run a big searchable combination database the way AMACO does. The combinations it prints itself are on its Nova and Ash color chart, which pairs each Ash glaze with an 1100 series glaze:
| Ash glaze | Paired with (1100 series) |
|---|---|
| 1421 Pear Ash | 1154 Text. Iron |
| 1422 Fig Ash | 1140 Text. Kiwi Fruit |
| 1423 Coffee Bean Ash | 1111 Holly Green |
| 1424 Cactus Ash | 1145 Text. Autumn |
| 1425 Kiwi Ash | 1115 Moonscape |
| 1426 Blueberry Ash | 1183 Dark Cloud |
The chart writes each pairing as "with" (for example "1425 Kiwi Ash w/1115") and does not spell out the order in the text we could read, so ask your dealer or fire both orders on test tiles. Note that 1424 Cactus Ash is a different glaze from 1438 Cactus in the Floating line.
Spectrum's older product guide adds two layering tips: soft reactive Nova glazes 1520 to 1525 work as a thin layer under the regular reactive Nova glazes 1530 to 1539, and the fluid 1173 Running Hot Chowder can go under or over other reactive glazes. We cover that glaze in Running Hot Chowder glaze combinations. The same guide warns against combining 900 Low Stone glazes with 700 glazes on one piece.
How to test Spectrum combinations
- Use tall test tiles with texture, made from the clay you will use.
- Brush the base glaze over the whole tile and the second glaze over the top two-thirds, so you see each glaze alone and together.
- Make a second tile with the order reversed.
- Stand tiles on a catch dish: running and floating glazes move more when layered.
- Fire to the cone you will use, note coats and cone on the back, and keep the tiles as your own chart.
Our glaze layering guide explains coat counts and drip control in more depth.
Spectrum underglaze
The 500 series is Spectrum's main underglaze, with 74 listings on its site and rated cone 06 to 6 on the color chart, marked lead free, non-toxic and dinnerware safe. Spectrum's product guide describes them as frit-based, so they can go on greenware or bisque, with or without a clear. It gives one coat as semi-transparent, two as semi-opaque and three as opaque. Without clear they fire to a matte, velvet-like surface, which Spectrum says is not dinnerware safe.
The 5500 One-Stroke colors are concentrated underglazes for opaque coverage in one stroke, and RAC (Raised Accent Colors) are slip-based colors in 8 oz bottles. For food surfaces, Spectrum's charts say underglazes, One-Strokes and RACs must be covered with a dinnerware-safe clear, naming Spectrum 1100 for mid-range and Spectrum 700 for low fire. Compare other brands in our best underglazes guide.
Low fire and high fire Spectrum lines
Low fire potters get 700 Opaque Gloss (56 colors), 800 Semi-Transparent, 900 Low Stone (stoneware-look glazes at cone 06/04), 250 Satin, 200 Rhinestone, 150 Metallic, 300 Majolica colors and crackle glazes. Spectrum's guide says 700 series opaques need two to three brush coats, and semi-transparents go on thin. See our low fire glaze guide for how these fit with other brands. The 1200 series covers cone 8 to 10, and the 850 raku line is for raku only.
Food-safety labels on Spectrum glazes
Spectrum labels each glaze with one of several icons on its color charts. The wording includes "Dinnerware safe. Contains no lead or cadmium ingredients," "Dinnerware safe. Contains no lead. Contains encapsulated cadmium pigment," and "Contains no lead or cadmium ingredients. May invite bacteria growth due to glaze fissures. Not recommended for surfaces which contact food or drink." The low fire chart also lists a label for glazes that contain heavy metals and "does not pass leach tests for metal release."
Two rules apply across the charts: glazes must be "fired to recommended firing temperature" to be dinnerware safe, and underglazes need a dinnerware-safe clear over them. Spectrum's 2026 price list adds that crackle glazes "cannot be dinnerware safe" and that raku firing makes every raku glaze unsuitable for dinnerware. Several colors also carry caution labels and are excluded from the "non-toxic" claim; on the 1100 chart that includes 1111, 1112, 1114, 1116 and 1154, among others.
A dinnerware label is the maker's result, not a promise about your pot. Fire to the stated cone, use a clay the glaze fits, avoid crazed or very runny surfaces on food areas, and test finished ware if you plan to sell it.
Prices and sizes
Spectrum's 2026 US suggested retail list puts most 1100 series pints at about $12 to $18, with a few specialty colors higher, and offers gallons and 10 lb dry bags. Floating pints run about $16 to $19.50, Nova brushing pints about $10 to $16.50, and 500 series underglazes come in 4 oz jars (around $8), pints and gallons. Dealer prices vary; check the live price.
Where to buy Spectrum glazes in the US
Spectrum Glazes is based in Concord, Ontario, Canada, and sells through distributors rather than its own US store. US dealers carrying Spectrum include The Ceramic Shop, Clay-King, Krueger Pottery, Sheffield Pottery and Bailey Pottery, and Spectrum's site links a US distributor list. Some pints also appear on Amazon from third-party sellers; check the series number and cone in the listing before you buy.
Where to start: three Spectrum jars
Spectrum 1100 Transparent
Picked because Spectrum names "Spectrum 1100" as its mid-range clear for covering underglazes on dinnerware, and it is in the lowest 1100 price group.
- Cone: 4/6 on site; chart says cone 5
- Finish: Gloss transparent
- Sizes: Pint, gallon, 10 lb dry
Pros
- Named by Spectrum as its mid-range clear
- Dry option for dipping
- Low price group
Cons
- Clears show flaws if applied thick
- Cone labels differ by source
Who should skip it: Low fire potters, who need Spectrum 700 clear instead.
Spectrum 1466 Celadon
Picked as an easy single-glaze start: a semi-transparent 1460 series glaze that pools in carving and stamps, from a line Spectrum marks dinnerware safe with exceptions.
- Cone: 4 to 6
- Finish: Semi-transparent gloss
- Sizes: Pint, gallon
Pros
- Shows off texture
- Simple to apply
- Sits in the lower price group
Cons
- Little effect on smooth forms
- Thick spots go dark
Who should skip it: Potters who want opaque, flat color.
Spectrum 500 Series Underglaze
Picked because it covers cone 06 to 6, works on greenware or bisque per Spectrum's guide, and comes in small 4 oz jars.
- Cone: 06 to 6
- Coats: 1 semi-transparent, 3 opaque (Spectrum guide)
- Sizes: 4 oz, pint, gallon
Pros
- Wide cone range
- 74 colors
- Small jar size
Cons
- Needs a clear for food surfaces
- Fewer US retailers than AMACO Velvet
Who should skip it: Anyone who wants a one-step color with no clear.
What Spectrum does well
- Layering-ready lines (Nova, Ash, Floating) aimed at cone 5/6 electric kilns.
- Large mid-range and low fire palettes from one maker.
- Dry 10 lb bags for the 1100 and Floating lines, useful for dipping buckets.
- Color charts list lead and cadmium wording by icon for each glaze.
Weak points
- Thin product pages: few coat counts, cone notes or firing tips online.
- Cone labels differ between site, charts and price list.
- Its current product guide is a download, and the easy-to-find edition online is from 2009.
- Fewer big US retailers than AMACO or Mayco.
Who should buy and who should skip
Buy Spectrum if you fire a cone 5 or 6 electric kiln, enjoy testing layers, and have a dealer that stocks it. Low fire potters who want a deep satin or Low Stone range will also find plenty.
Skip it if you want detailed online instructions and a searchable combination library, or if you only shop big-box stores. In that case AMACO or Mayco is easier.
Alternatives
- AMACO glazes: Potter's Choice and Celadon, with a large layering database.
- Mayco Stoneware glazes: cone 5/6 to 10 reactive glazes with clear labels.
- Coyote glazes: a cone 6 favorite for shinos and reactive colors.
- Clay and glazes hub: every glaze brand and line we cover.
Sources: spectrumglazes.com home, Glazes, High Fire Cone 4/6, Cone 9/10, Mid Range, Low Fire, 500 Series Underglazes, 1100, 1420 Ash and 1430 Floating category pages and 1100 Transparent and 1435 product pages; Spectrum color charts 1100, 1500/1420 (Nova and Ash Layering Glazes), 1200/1460, 1400, 1430, 700, 900, 500 and 300; Spectrum 2026 USD price lists (high fire, low fire, decorating colors); Spectrum Health and Safety (SDS), Distributors and Educational Resources pages; Spectrum Product Guide 2009 (dealer-hosted PDF); dealer pages from The Ceramic Shop, Sheffield Pottery, Bailey Pottery, Clay-King and Krueger Pottery; Glazeshare user combinations; Amazon search results for Spectrum pints. Research-based, not hands-on. Specs checked October 2026.