Stained engobes can be applied thinly yet fire opaque

Monday 23rd July 2018

This black engobe, L3954F, is on a cone 6 buff stoneware (at leather hard stage). It contains only 7.5% Mason 6600 black stain. How is that possible? Why do people add so much more to their insight-live.com/glossary/92">underglazes? Because this recipe has been tuned to have the same degree of maturity as the body, it therefore fires totally opaque. This contrasts with other underglaze/engobe recipes containing significant frit, among other issues, their vitreous nature renders them translucent. Thus, up to 40% stain is needed to crowbar their opacity enough to intensify color. And a thicker application (that carries other issues).

This has dried long enough to be able to touch the engobe. Notice how thinly and evenly the coverage is. This cannot be done with a brush; it has to be done by dipping. This was possible because of another key factor: The slurry was adjusted, just before use, to be thixotropic. The thinner layer enables drying more quickly. This engobe was designed to be compatible with this body (meaning fewer issues with flaking during drying, better fire-fit).

Pages that reference this post in the Digitalfire Reference Library:

Absolutely Jet-Black Cone 6 Engobe on M340 This could also be super white, The best way to make black clay: Don't. Use an engobe instead., Make a black engobe to fit your stoneware perfectly, Engobe

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