AMACO Blue Rutile is PC-20 in the Potter's Choice line, a cone 5 to 6 brushing glaze that is "a flowing light blue where thick and breaks brown where thinner." AMACO says it is "always one of our top selling Potters Choice glazes", and it is the glaze many home potters picture when they hear "AMACO blue". This review covers its look, coats, how much it runs, its food label, the formats AMACO sells and the combinations AMACO publishes for it.
It is research-based. We worked from AMACO's product and line pages, its 2026 Complete Guide, its Potter's Choice product sheet, AMACO blog posts and dealer listings. We have not fired it. Results described here are AMACO's.
Verdict
Blue Rutile earns its reputation for textured, layered work. It is active and unpredictable in a way many potters like: blue pools, brown edges and movement over carving. AMACO publishes more combinations for it than for almost any other Potter's Choice color.
The cost is control. AMACO itself calls it "a very fluid glaze", thin coats look patchy according to dealer guidance, and thick coats run. Buy it if you will make test tiles and protect your shelves. A pint typically costs about $20 to $30 at US sellers in October 2026, and a gallon costs several times that; check the live price.
PC-20 Blue Rutile specs
| Spec | AMACO figure | Notes |
|---|---|---|
| Code and line | PC-20, Potter's Choice | Listed under Mid-High Fire Glazes |
| Cone | 5 to 6 | Cone 5 = 2,167°F (1,186°C), cone 6 = 2,232°F (1,222°C), medium-speed firing |
| Bisque | Cone 04, 1,945°F (1,063°C) | From the Potter's Choice line page |
| Coats | Not on the product page | 3 to 4 general (Complete Guide); 3 thick coats (The Ceramic Shop) |
| Finish | Opaque icon; "very fluid" | Blue where thick, brown where thin |
| Spraying | No-spray icon on the product page | One EU dealer says compressor safe; follow AMACO's page |
| Formats | Pint, gallon, dry dipping mix | Dry size not listed on AMACO's page |
| Food label | Food safety status per PC product sheet | No Food Safe icon on the product page in our check |
| Status | Current | In stock at AMACO, October 2026 |
Cone temperatures differ by source. AMACO lists cone 5 at 2,167°F (1,186°C) and cone 6 at 2,232°F (1,222°C) for a medium-speed firing. The Ceramic Shop lists 2,201°F (1,184°C) and 2,266°F (1,241°C), based on a slower final climb of 270°F per hour over the last 200°F. Both describe the same cones; the heating rate changes the end temperature.
Is Blue Rutile discontinued? Status and formats
No. PC-20 is current on AMACO's Potter's Choice page in October 2026, listed as in stock, with no change of name or code. AMACO sells it three ways:
- Pint: the brushing glaze most home potters buy.
- Gallon: the same brushing glaze in a larger jar.
- Dry dipping mix: mentioned on the product page, which notes that the dry version's "health information and labels differ from the brushing glazes" and that "all dry dipping glazes can be difficult to layer." AMACO's page does not list the dry bag size.
There is no other AMACO glaze called Blue Rutile. AMACO's 2026 Complete Guide lists PC-20 as the only one; the only other rutile product in it is TH-1 High Fire Texturizer, which AMACO calls "a rutile-based glaze changer", not a glaze. On the product page AMACO now links PC-20 to the new PC-18 Tuscan Blue, which is a different, semi-matte blue covered in our AMACO Moon River and named glazes roundup.
What Blue Rutile looks like
AMACO's full description: "Great for layering and textured work, Blue Rutile is an active, complex glaze that is a flowing light blue where thick and breaks brown where thinner." The Complete Guide places it in its "Flows and Floats" group of Potter's Choice glazes.
That thick versus thin contrast is the whole character of the glaze. On a carved or stamped pot, glaze collects in the low spots and turns blue, while edges and high points stay thin and go brown. On a smooth, evenly coated surface you get less contrast. AMACO's product sheet shows one, two and three coat tiles at cone 5, and the color moves from brown toward blue as the coats build.
What is a blue rutile glaze?
A blue rutile glaze is a fluid glaze with rutile added, a mineral that supplies titanium and some iron. According to Digitalfire's glossary, the blue comes mainly from titanium rather than cobalt, as tiny crystals form during cooling, which is why slow cooling usually strengthens the effect. Thin areas tend to stay brown, and too much rutile makes the surface rough.
Digitalfire also notes that rutile blues are sensitive to chemistry and firing schedule and that dark-burning bodies generally give better blues. That is general glaze behavior, not an AMACO claim about PC-20, but it explains why your Blue Rutile may not match the jar photo. For the wider family of glazes that change with thickness and cooling, see our reactive glaze guide.
Blue Rutile on light and dark clay
AMACO's PC-20 page does not show the glaze on different clay bodies. The nearest AMACO guidance is in its customer favorites post, where PC-25 Textured Turquoise over Blue Rutile is described as showing best on lighter clays but "lovely on dark clays" too, and all the examples were fired on AMACO No. 11 A-Mix White Stoneware.
So treat any jar photo as a white-clay result. On buff or red stoneware, expect the brown break to blend more with the clay and test before committing a set of mugs.
How to apply Blue Rutile
AMACO's PC-20 page gives no coat count. Its Complete Guide says, "We typically recommend 3-4 coats when using AMACO brushing glazes," and The Ceramic Shop recommends three thick coats, warning that a thin application looks splotchy. In AMACO's own layered examples, Blue Rutile goes on at about two coats.
- Bisque to cone 04 and wipe the pot with a damp sponge.
- Wax the foot and the bottom quarter inch or so with wax resist.
- Brush the first coat, let it dry, then repeat for three coats in total on a stand-alone piece.
- Keep the lowest band thinner than the rim, because the glaze will move down.
- Fire to cone 5 or 6 on a cookie or with kiln wash on the shelf.
AMACO also recommends firing a test tile before using each new batch number. General brushing technique is covered in how to glaze pottery.
Run risk
Take AMACO at its word: "A very fluid glaze." Three heavy coats to the foot is the classic way to glue a pot to a shelf. Leave a gap above the foot, fire your first pieces on a cookie, and remember that cone 6 moves more than cone 5. AMACO's note on the Textured Turquoise pairing, fire to "cone 5 or 6, not hotter", applies to Blue Rutile in general: do not push it past cone 6.
Putting a flux over it, such as PCF-54 Flux Blossom, adds even more movement. Our AMACO glaze layering guide covers drip control for stacked glazes in detail.
AMACO's published Blue Rutile combinations
AMACO names each combination top glaze first, so "PC-20 over C-36" means Blue Rutile is on top. The best-documented example comes from AMACO's customer favorites post: two coats of PC-25 Textured Turquoise over two coats of PC-20 Blue Rutile, cone 5 or 6, "a bit runny", with more tan float when fired hotter. Textured Turquoise has its own page: AMACO Textured Turquoise.
Blue Rutile on top
- Over Celadons: C-10 Snow, C-11 Mixing Clear, C-32 Ochre and C-36 Iron.
- Over Potter's Choice: PC-17 Honey Flux, PC-21 Arctic Blue, PC-29 Deep Olive Speckle, PC-33 Iron Lustre, PC-40 True Celadon, PC-41 Vert Lustre, PC-44 Sage, PC-56 Ancient Copper and PC-59 Deep Firebrick.
Blue Rutile as the base
- PC-25 Textured Turquoise, PC-34 Light Sepia, PC-41 Vert Lustre, PCF-54 Flux Blossom, PC-64 Aventurine and PC-04 Palladium over PC-20.
Coat counts for the database entries sit on each AMACO entry; we list only the names here. Two cautions. First, PC-04 Palladium and PC-64 Aventurine are the glazes AMACO excludes from its Potter's Choice food safety status, so keep those pairings off food surfaces. Second, the Honey Flux pairing is covered in Honey Flux combinations, and Iron Lustre and the other named glazes in our AMACO named glazes roundup.
Is Blue Rutile food safe? What the labels say
AMACO's current Potter's Choice product sheet says all Potter's Choice glazes "hold a food safety status" except PC-4 Palladium, PC-9 Vintage Gold and PC-64 Aventurine. PC-20 is not on that exception list, and The Ceramic Shop and a European dealer both list it as food safe.
The PC-20 product page itself showed the AP seal, a cone icon, an opaque icon, a no-spray icon and one unlabeled icon in our October 2026 check, but not AMACO's Food Safe icon, which other AMACO pages do show. AMACO also says AP or CL certification does not decide food safety.
We cannot promise Blue Rutile is food safe on your pots. Any label assumes the glaze is fired alone to cone 5 to 6 on a suitable clay. A fluid glaze that is underfired, applied very thick or layered with another glaze is a new surface. Use AMACO's SDS for handling, and see our food safe glaze guide for testing before you glaze the inside of a mug.
What Blue Rutile does well
- Strong contrast over texture: blue in the recesses, brown on the edges.
- One of the longest lists of AMACO-published combinations, as top coat and base.
- Three formats, from a pint for testing to dry mix for dipping.
- A cone 5 to 6 range that suits most home electric kilns.
Weak points
- "Very fluid" by AMACO's own description, so shelf protection is not optional.
- No coat count on AMACO's product page; sources range from two to four coats.
- Thin coats look patchy and brown, so results vary a lot with brushing.
- Food Safe icon missing from the product page despite the product sheet statement.
- The dry dipping version needs its own testing, especially for layering.
Who should buy, and who should skip
Buy Blue Rutile if you fire to cone 5 or 6, make textured or carved work and enjoy layering. It is a sensible second or third glaze once you have a clear and a stable base.
Skip it if you want a flat, even blue for a matching dinner set, if you glaze all the way to the foot, or if your kiln only reaches cone 05. Beginners who do not yet use cookies or kiln wash should start with a stiffer glaze.
Alternatives
- PC-18 Tuscan Blue: AMACO's new semi-matte deep blue that breaks to moss green, for a calmer surface.
- PC-21 Arctic Blue: a lighter Potter's Choice blue and a common Blue Rutile partner.
- PC-23 Indigo Float: a deeper, intensely blue float glaze.
- Mayco SW-101 Stoned Denim: Mayco describes it as "a variegated blue glaze that breaks brown", with samples at cone 5 to 6 and cone 10 and a Dinnerware Safe logo on its page.
For the rest of the line, see our Potter's Choice review.
Safety notes
Glaze dust contains silica. Clean spills wet and never dry sweep. Wear a NIOSH-approved respirator when mixing the dry dipping version, and read AMACO's SDS before use. Fire in a kiln with the clearance and ventilation its maker specifies.
Sources: AMACO product page for PC-20 Blue Rutile and Potter's Choice line page (shop.amaco.com); AMACO Potter's Choice product sheet (amaco.com asset); The Complete Guide to AMACO Clay, Glazes, Underglazes (published 2026); AMACO blog "Customer Favorite AMACO Glaze Combinations to Try"; AMACO layering database entry titles; The Ceramic Shop PC-20 listing; 1240.design PC-20 listing; Mayco SW-101 Stoned Denim product page; Digitalfire glossary entry on rutile blue glazes. Research-based, not hands-on. Specs checked October 2026.