Seaweed over Cobalt Combo by Shell Con

Rainbow Glaze Combo with Seaweed and Cobalt

This colorful mug by Shell Con demonstrates how layered commercial glazes can create a full spectrum of color on a single ceramic surface. Made from stoneware and fired to Cone 6, the piece combines warm amber, vibrant red, turquoise, green, and deep blue tones that flow naturally around the form. The glaze arrangement creates horizontal bands of color that resemble the changing sky at sunset, moving gradually from warm hues near the rim to cooler tones lower on the vessel.

The Rainbow Glaze Combo begins with three coats of AMACO Ancient Copper around the rim, establishing a rich copper-red foundation. The lower two-thirds of the mug are covered with three coats of AMACO Cobalt, providing the deep blue base that supports the rest of the composition. Three coats of AMACO Seaweed are layered over the surface, excluding the lower third, allowing the glazes to blend where they overlap. A thin line of AMACO Oatmeal is applied where the glaze sections meet, creating lighter transitions and highlighting the boundaries between colors.

Cone 6 Rainbow Glaze Effects on Stoneware

During firing, the overlapping glazes develop a wide range of colors without losing definition between the layers. Ancient Copper contributes warm reds and golds, Seaweed introduces green and teal tones, while Cobalt anchors the composition with deep blues. The result is a balanced Cone 6 glaze combination that demonstrates how carefully placed glaze layers can produce complex color transitions across a simple mug form. For potters exploring colorful glaze layering, this piece offers an excellent example of a successful Rainbow Glaze Combo.

Author

Shell Con

Clay Body

Stoneware

Glazes

• AMACO Ancient Copper ×3 (rim)
• AMACO Cobalt ×3 (lower two-thirds)
• AMACO Seaweed ×3
• AMACO Oatmeal (transition line)

Cone

The mug is fired to Cone 6

Credit: Shell Con