Description

Northcote Underglaze is suitable for all the Northcote Pottery clay bodies listed. Colours can be blended and will hold their form unlike glazes which melt and become fluid when fired. For best coverage, apply 2 thin even coats with a soft brush. Underglazes can be made glossy by the application of a clear glaze over the top. Underglaze must be fired in a kiln. Burnout temperature: 1300°C. Prices vary depending on the colour. Please see the colour chart. Please Note: Royal Purple is a Price 4. Earthenware Glazes and Stoneware Glazes available.

How to use Northcote Underglaze:

Stir Northcote underglaze thoroughly before and during use, then apply 2–3 thin, even coats with a soft brush, allowing each to dry until no longer shiny between layers. It can be used on raw (leather-hard) or bisque-fired clay. Avoid applying more than three coats to prevent peeling. Once dry, you may apply a clear glaze over the top before firing. Always test under your specific firing conditions as results vary.

Detailed Usage Guidelines for Underglaze:

Preparation & Application

• Surface: Ensure your clay piece is clean, dust-free, and grease-free. Sponge the surface lightly before beginning if necessary.
• Stirring: Underglaze ingredients settle over time. Stir well before starting and stir regularly while working to maintain consistent colour and thickness.
• Brushing: Use a soft, high-quality brush. Apply thin, even layers. If you apply it too thickly, it may crack or peel during firing.
• Layering: Allow each coat to dry to the touch (losing its shine) before applying the next. Two to three coats are generally sufficient for opaque coverage, though lighter colours may require more.

Tips for Success

• Thinning: To thin the underglaze, use a dedicated brushing medium. While water can be used for spraying or dipping, it may cause separation or settling in the jar if mixed into the main supply.
• Blending: Mix different Northcote underglaze colours to create custom shades. Always test a small amount first to ensure the result is what you expect after firing.
• Techniques: Try sponging, stencilling, or trailing your underglaze. Water your underglaze down significantly to achieve a watercolour-like, wash effect.
• Storage: Keep lids tightly closed when not in use. Underglaze cannot be re-hydrated once dry in the jar..

Firing & Finishing

• Glazing: While you can leave underglaze unglazed for a matte finish, applying a suitable clear glaze over the top will seal the surface and provide a glossy, food-safe finish.
• Do Not: Never apply underglaze over a fired glaze surface, as it will not adhere properly.
• Testing: Because clay bodies and kiln atmospheres vary, always perform a test piece under your specific firing conditions before committing to a final project.