Frequently Asked Questions: Kiwi Underglazes

What is a Kiwi Underglaze?

Kiwi Underglazes are highly pigmented liquid colors used for decorating and painting ceramics. Because they do not contain glaze components (and therefore won't melt or run during firing), your designs stay sharp and precise. They are typically covered with a clear top coat glaze to add shine and protection.

 

Can Kiwi Underglazes be mixed together?

 

Yes, absolutely! You can mix different shades together just like regular paints to create custom colors. You can also dilute them with a splash of water for watercolor-like effects or apply them thickly for opaque, solid coverage.

 

Which clay bodies and firing temperatures are they suitable for?

Kiwi Underglazes are exceptionally versatile and perform beautifully across a wide temperature range, from low-fire earthenware up to high-fire stoneware.

  • Icewood Atelier Tip: While reds and other sensitive warm tones from many manufacturers tend to fade or burn out at high stoneware temperatures, we have personally tested Kiwi’s most critical colors (including the red!) in our own studio. They remain wonderfully bright and vibrant even in high firings! However, we always recommend firing a test piece with your specific clay and clear glaze combination.

 

Can they be applied to greenware (raw clay) or bisqueware?

 

You can use both techniques depending on your workflow:

  1. On leather-hard / greenware clay: An excellent choice if you want to carve designs through the color layer (sgraffito technique).
  2. On bisqueware: The most traditional and easiest method for painting crisp, detailed patterns.

 

Are Kiwi Underglazes food-safe?

The underglazes themselves are non-toxic and lead-free. Because an unglazed underglaze surface remains matte and porous after firing, your finished pieces become food-safe only when covered and fired with a food-safe clear top coat (clear glaze).

 

How many layers of underglaze should I apply?

  1. 1 layer: Yields a light, translucent, or watercolor-like finish.
  2. 2–3 layers: Provides complete, opaque, and intense color coverage. Let each layer dry slightly before applying the next.

 

Do underglazes always require a clear glaze on top?

Not necessarily. If you want a completely matte, slightly textured, or velvet-like accent on your piece, you can leave the underglaze exposed. Keep in mind, however, that without a clear glaze, the surface will not be food-safe or fully stain-resistant (for example, on the inside of a mug).