When is a piece food safe?

A glaze does not make a piece safe on its own — safety depends on the right glaze, the right application and the right firing. In the catalogue every line carries one of these notes:

“Food safe under clear glaze”

Underglazes and colours (Underglaze, One Stroke, Café Color, pencils, chalk, 3D Trailing). On their own they don’t form a sealed, glassy surface. For food contact, brush or dip clear glaze over them and fire within its range. Without clear glaze — decorative pieces only.

“Food safe when fully covered”

Glazes such as Superior Glaze, Low Sheen, Matt Glaze H, Pastel Glaze H, Stoneware Exotic. There are two conditions:

1. the food-contact surface must be covered completely, with no bare spots;
2. the piece must be fired within the glaze’s range.

Some Stoneware Exotic colours are sensitive to acidic and alkaline food and are not meant for food — the list is on the line’s page.

Café Color G — a special case

If the piece is covered entirely with Café Color G and correctly fired, it is food safe even without clear glaze. If you use colours from other series too, the whole piece must be covered with clear glaze.

“Not food safe”

• Crackle glazes: bacteria collect in the cracks.
• Crystal and textured glazes (Fantasy, Supernova, Crystallite, Volcano, Textured, Antique): the surface is uneven or may craze.
• Raku: a decorative technique.
• Lines containing lead (Feng Shui and some Stoneware Exotic colours): for decorative, professional or studio use only. Don’t use them in group classes with children.

These glazes can be used on the outside of functional ware — for example on the outside of a cup whose inside has a food-safe glaze.

“No firing”

Acrylic, pearlescent, metallic and sand-texture paints are not fired and are not meant for food.

This information is based on the manufacturer’s labels and catalogue. The final result depends on the application, the clay and the firing; if you make pieces for sale, we recommend a test tile and a correct firing schedule.