Main firing
The glazed fabric is fired at a higher temperature than unglazed at about 1,300°C for about 15 hours. The purpose of the main firing process is to coat the fabric with glaze to eliminate water absorption and make it strong enough to be used as tableware, and to make the underglaze painting and glaze vividly colorful through chemical reactions during the firing process. In Arita-yaki, reduction firing produces beautiful white porcelain and a deep lapis lazuli color.
After firing, all products are inspected and only the good ones are transferred to the painting process.
本焼成
施釉まで終えた生地を、素焼きよりも高温の約1300℃で約15時間ほど焼成します。生地を釉薬でコーティングし吸水性をなくし食器としての強度を得ることと、焼成の際の化学反応により下絵・釉薬を鮮やかに発色させることが本焼成の目的です。有田焼では還元焼成（Reduction firing）することで美しい白磁と深い瑠璃色を生み出します。
本焼成を終えた製品は、全数を検品して良品のみを絵付け加工の工程に移します。
