Copper-Red Glazed Studio Mug — Oxblood Drip Glaze, Crackle Interior

A small, hand-thrown mug with a rounded, ear-shaped handle, dipped in a rich copper-red (oxblood/sang de boeuf-style) glaze. The reduction-fired copper glaze breaks and mottles across the body — deep maroon pooling near the base, thinning to lighter rose tones and small pitted specks near the rim — a classic effect of copper-red glazes reacting under variable kiln atmosphere.

The interior and rim are left in a contrasting pale, crackled glaze, creating a striking two-tone effect between exterior and interior. The unglazed footring exposes a warm orange-buff stoneware body, with a carved seal mark visible in the centre, indicating a specific kiln or maker.

Copper red glaze is called shinsha (辰砂) in Japanese ceramics (also seen as kōyū/紅釉 or, for Chinese-origin ware, rōkōyū/郎紅釉). It's a notoriously difficult glaze to fire correctly — the copper oxide is highly sensitive to kiln atmosphere, so achieving an even, vivid red without going brown, grey, or blotchy has historically been considered a mark of skill. This technical difficulty is part of why it carries prestige in Japanese ceramics circles, especially in Kyoto-yaki, Kutani, and studio-potter work.

Details:

• Form: Small rounded mug with loop handle

• Glaze: Copper-red (oxblood) reduction glaze on exterior, contrasting pale crackle glaze on interior/rim

• Surface: Mottled, pitted copper-red tones from reduction firing; visible glaze pooling at base

• Base: Unglazed footring, orange-buff clay body, carved seal mark

• Condition: Small black speck/inclusion visible on body — check in hand; crackle glaze is characteristic, not damage; inspect handle join for hairline stress cracks

• Capacity: approx. 120ml

• Dimensions: (L) 7.7cm x (H) 6.3cm