AMACO Potter's Choice Flux (PCF): Specialized glazes for layering and flow effects

With the Potter's Choice Flux series (PCF for short), AMACO has created a unique line of glazes entirely dedicated to flowing and running. The series' subtitle sums it up perfectly: "Designed for movement and flow."

While classic Potter's Choice glazes are known primarily for their reduction-fire aesthetic, the PCF glazes are designed to move, react with other glazes, and create soft, flowing transitions when layered.

Here at Formwerk Pottery Supplies Berlin, this post explores the PCF series, the philosophy behind it, the colors available, how to apply them, and which combinations will help you achieve the most beautiful flow effects.

Have fun with the PCF glazes!
Your Formwerk Team ❤️

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What is the Potter's Choice Flux series?

The PCF series is a standalone glaze line from AMACO for mid-range firing at Cone 5 to 6, which corresponds to temperatures between 1,186 °C and 1,222 °C in a standard electric kiln. It currently comprises twelve colors and is based on the formula of one of the most popular Potter's Choice glazes of all time: PC-17 Honey Flux. AMACO took this proven, highly fluid base and developed an entire color family from it.

The decisive difference from the classic PC series: PCF glazes are not effect glazes with "built-in drama," but rather soft, pastel tones whose strength lies in their interplay. They can be used on their own, but they unfold their full potential when layered. Applied over or under other glazes, they soften their colors and cause them to flow. That is exactly what they were made for.

What does "Flux" mean? Flowing glazes explained

A quick note on terminology, as it can easily lead to confusion: In glaze chemistry, a "flux" refers to a raw material that lowers the melting point of a glaze, such as feldspar, lime, or borax. That is not what is meant here. AMACO uses "Flux" in the series name as a description of behavior: these glazes melt more softly, exhibit more movement during firing, and react more intensely with the glazes they are layered with.

In everyday pottery, one would most likely refer to these as flowing glazes or gradient glazes. Practically speaking, this means: a PCF glaze under a Potter's Choice glaze will cause it to run, creating soft transitions and drips. A PCF glaze over a strong color will lighten it and encourage flow. On textured surfaces, the glazes break and allow the clay color to show through.

Flux in action: PCF-74 River Birch running over C-29 Deep Sea, forming soft transitions and drips. Fired at Cone 6. Photo: AMACO Brent.

Firing temperature and technical specifications

The PCF series shares its firing conditions with Potter's Choice and Celadon glazes. This makes all three series easily combinable in the same firing:

We explain in detail what firing cones mean and the temperatures behind Cone 5, 6, or 04 in our post Pyrometric cone values.

The twelve colors of the PCF series

The series started with six colors and has since been expanded to twelve. The palette is intentionally soft: many pastel tones that work well as a base or top coat with bolder glazes. We have grouped them here by color world; this classification is our own, not AMACO's.

Blue and Gray

PCF-3 Midnight Run is the series' dark, velvety blue-gray and the most high-contrast tone in the palette. PCF-21 Ocean Drift provides a light, speckled blue, and PCF-19 Cirrus Flow offers a delicate, cloudy light blue.

The color PCF-3 Midnight Run

Green

PCF-18 Honeydew is a light yellow-green, named after the honeydew melon. PCF-75 Moss Mist provides a delicate, misty moss green with light marbling.

The color PCF-18 Honeydew

Pink and Warm Tones

PCF-54 Flux Blossom is a pale pink that develops a peach-colored float when applied thickly. PCF-36 Rose Mist leans into a soft rosé with a gray undertone, and PCF-16 Aurora Breeze shows a bright, creamy-pink base with fine dark speckles.

The color PCF-54 Flux Blossom

Yellow and Earth Tones

PCF-60 Sun Beam is a soft sun yellow, PCF-63 Sun Shower is a light yellow with fine dark speckles. PCF-74 River Birch is a bit different: a creamy base tone with striking brown speckles reminiscent of birch bark. PCF-33 Mystic Tide is the most striking glaze in the series, shifting between green-gray and rusty orange tones.

The color PCF-63 Sun Shower

Overview of the complete Potter's Choice Flux collection.

Application: Applying thickly pays off

PCF glazes are applied by brush onto bisqueware fired at Cone 04. As with Potter's Choice glazes, the same applies here: most PCF glazes benefit from a strong, generous application. In the series brochure, AMACO shows the same color in one, two, and three coats, and the difference is clearly visible. Only from about three coats do the glazes develop their full color depth and characteristic flow. A thicker application always means more movement in the firing.

Same glaze, different number of coats: 1, 2, and 3 applications compared, fired at Cone 5.

You can find more about bisque firing and why the correct temperature is crucial in our post What is a bisque fire?

Layering: The strength of the series

Layering, or brushing different glazes over one another, is the true purpose of the PCF series. AMACO explicitly states that these glazes are suitable for combining with Potter's Choice glazes, AMACO Celadons, and AMACO Shino glazes. PCF glazes work in both directions, as either a bottom or top layer.

These tested combinations are taken from the official AMACO brochure, many of them featuring glazes you can find directly in our shop:

• PCF over PCF: PCF-19 Cirrus Flow over PCF-54 Flux Blossom, or PCF-3 Midnight Run over PCF-19 Cirrus Flow
• PCF over Potter's Choice: PCF-19 Cirrus Flow over PC-45 Dark Green, or PCF-74 River Birch over PC-62 Textured Amber Brown
• Potter's Choice over PCF: PC-52 Deep Sienna Speckle over PCF-54 Flux Blossom, or PC-26 Blue Lagoon over PCF-75 Moss Mist
• PCF over Celadon: PCF-3 Midnight Run over C-36 Iron, or PCF-54 Flux Blossom with C-54 Snapdragon
• PCF via Shino: PCF-19 Cirrus Flow over SH-41 Oolong Gloss, or PCF-74 River Birch over SH-52 Hibiscus Matte
  
  

Tested layering combinations from the official AMACO brochure.

You can find further tested pairings with application instructions in the official AMACO layering charts. And as always: before your first attempt on a finished piece, it is better to fire a test tile. Every kiln, every clay, and every hand applying the glaze will yield slightly different results.

The influence of the clay body

Precisely because many PCF glazes are light and delicate, the clay color plays a major role in the final result. AMACO demonstrates this in the brochure using the example of PCF-16 Aurora Breeze on three different clay bodies: on light clay, the glaze appears friendly and pastel; on dark clay, the speckles and breaks become significantly more dramatic because the dark shard shines through at the break points.

The sample tiles in the series are fired at Cone 5 on AMACO 11-M A-Mix White Stoneware. Those wanting to achieve similar results are best guided by a light stoneware. You can find suitable clay bodies in our stoneware assortment.

Food safety and security

Here, the PCF series has a real advantage over the classic PC series: All twelve PCF glazes are food safe. AMACO answers this question clearly in the official series FAQ, and the glazes bear the Dinnerware-Safe label. There are no exceptions as with Potter's Choice, where three glazes are for decorative use only.

The glazes also bear the AP seal according to ASTM D-4236, the US standard for the safety of art materials, and are suitable for spray application according to AMACO. The prerequisite for food safety is, as always, the correct, full firing at Cone 5 to 6. A glaze fired too low will not fully bond and should not be used for dinnerware.

Frequently asked questions about the PCF series

What distinguishes PCF from the normal Potter's Choice glazes?
The PCF series is based on the highly fluid formula of PC-17 Honey Flux and is specifically designed for movement and flow. The colors are predominantly soft pastel tones that brighten and create flow in other glazes when layered. The classic PC series, on the other hand, relies on independent, dramatic effect glazes.

Can I use PCF glazes on their own?
Yes. AMACO explicitly mentions both applications: on their own for soft, monochromatic surfaces or layered for flow effects. They look very nice solo, especially on textured surfaces where the glaze breaks and reveals the clay color.

Are all PCF glazes food safe?
Yes, according to AMACO, all twelve glazes in the series have food-safe status. The requirement is a full firing at Cone 5 to 6.

Why does my PCF glaze run onto the kiln shelf?
PCF glazes are intentionally fluid, and thick application plus Cone 6 intensifies the movement. Apply less in the bottom third, leave a bare space at the base, and place pieces on a kiln shelf treated with kiln wash. If you want to be on the safe side, fire at Cone 5 first; the glazes remain calmer there.

Do I need the PCF series if I already have PC and Celadon glazes?
It is the ideal complement, as that is exactly what it was built for. All three series fire in the same range, and the PCF glazes act as a connecting link: they set existing PC and Celadon colors into motion and open up new combinations without you having to change your firing program.

Conclusion: the connecting link in the AMACO Cone 5/6 system

The Potter's Choice Flux series is not a collection for a big solo performance, but rather the tool for those who want more control over flow and color impact when layering. Twelve soft colors, completely food safe, in the same firing range as Potter's Choice and Celadon, and with a formula that builds on one of AMACO's most popular flow glazes. Those who enjoy layering will get a lot of joy from this series.

The three most important points for good results: apply generously, work more sparingly at the bottom of the piece, and fire a test tile before trying new combinations. In our Formwerk-Berlin assortment, you will find PCF glazes in 472 ml containers, along with the matching Potter's Choice and Celadon series for combining. If you have any questions about selection, we are happy to advise you.

Sources

Note: All information regarding firing temperatures, coating thicknesses, and layering combinations are guide values based on manufacturer specifications and our consulting experience. Actual results may vary depending on the kiln, firing curve, clay type, and individual application. We always recommend test tiles before mass production.

The Formwerk-Berlin team wishes you much success with your Potter's Choice Flux glazes