Eclipse Pottery Clay

SKU: 12698B Brand: Seattle Pottery Supply    


12698B 25 Pound 154 in stock Available $34.00
12698B5 5 Pound Out of Stock Backorder $19.00

*Back orders will be placed for order quantities exceeding that of on-hand inventory.

Block weight: available in 25 lb and 5 lb blocks. NOTE: shipping is included in the price of the 5 lb block!


  • Wet Color: Red
  • Firing Color: very dark gray; black when glazed
  • Texture: Slightly Smooth (< 5% grog)
  • Avg. Shrinkage 2±%: 12.5% at cone 5

Eclipse is a very dark gray mid-range stoneware clay body that fires to black when glazed. Designed to replace (and one-up) our old Midnight Black clay, it is formulated with lower manganese levels for user safety. Stronger and less likely to bloat than previous dark clays, it fires to 0% porosity to ensure strength, good glass development, and a body that can be put to the test. It has a rich, sophisticated color when unglazed, and offers a fantastic contrast for marbling or combining with lighter clays.


As most potters know, dark clay bodies are beautiful, but definitely can be finicky to work with. These are our top tips to ensure the most success in your pieces when working with a dark clay body!

  • Clays with heavy colorants need room for off-gassing. We recommend avoiding tightly packing your bisque fire for optimal results with our darker clays.
  • We recommend using a slow bisque schedule and a fast glaze setting while firing your pieces. This will allow for more off gassing during the bisque firing, and reduce the amount of heat work in the glaze firing.
  • We also recommend glaze firing to Cone 5 with a witness cone. While our clays can perform at Cone 6, the best and most reliable performance will be seen at Cone 5. See photo to the left, with examples fired at cone 04, cone 5 and cone 8.

We like it for throwing, handbuilding, dinnerware, tile, sanitaryware, jiggering/jollying, and pressing. We hope you enjoy Eclipse!

Ships USPS in a flat rate box.

To use: wedge wet clay, work as preferred, and fire to ∆ 5. Use with mid-range glazes.

*Please be aware that natural impurities may occasionally occur in our clay! Our clays are made with natural minerals, mined from the earth. In some rare cases, natural impurities, or ribbons of other minerals, are mixed in with the raw materials provided by our suppliers. This can lead to clays that don’t perform the way they are supposed to. If you have any questions about a particular clay body, please reach out to

The new, new.

Our replacement for Midnight Black. It has a rich and sophisticated color, but is formulated with lower manganese levels for safer handling.

Embrace the dark side (of pottery).

It's deep, dark color is a fantastic contrast for marbling and techniques like Nerikomi (seen here with our CKK6 white clay)

Take it for a spin.

Built strong, Eclipse is good for throwing those tall and dramatic vessels!