With this technique, you can paint designs with pigment containing iron oxide (rusted iron), then coat it with a glaze that turns transparent during firing, and fire it at a high temperature (glost firing). This is a basic method of producing decorative ceramics, utilizing the way the iron in the pigment changes colors when fired.
Did you know?
The pigment known as zaffer is black or brown before firing, but it turns a beautiful deep blue during glost-firing. The subtle differences in color resulting from the artist’s brushstrokes or variations in pigment thickness are part of what makes blue and white ware so enchanting.
How to make blue and white ware
"What Are Traditional Crafts? -A Guidebook to Seeing, Learning, and Enjoying-" Edited by the Japan Kogei Association Eastern Branch. Published by Unsodo ／ List of works English translation: Kazuko Todate (Art critic / Art historian)