Mastering Ru Ware in 1 Minute: The Five Defining Features

Ru ware (汝窑) is one of the most celebrated ceramics of the Song dynasty, admired for its elegance, rarity, and natural beauty. In this article, we’ll walk through the five defining features of Ru porcelain that set it apart from all other wares.

1. Sky Blue Glaze 

The signature “sky blue” of Ru ware is not a single shade but rather a color band inspired by nature itself. Just like the sky gradually shifts from the horizon upward, Ru porcelain’s glaze reflects a subtle spectrum of blues, soft and ethereal, evoking the changing heavens.

2. Jade-like Texture

Beyond its color, the essence of Ru porcelain lies in its smooth, lustrous glaze — warm and delicate like jade. In Chinese culture, jade represents nobility and virtue, which is why Song dynasty literati treasured Ru ware as much as fine jade.

3. Cicada-Wing Crackle 

Because the glaze and clay body expand and contract at different rates during firing and cooling, thin crackle lines naturally form across the surface. These delicate, uneven fissures resemble cicada wings, giving each piece a unique character.
In addition to cicada-wing crackle, Ru ware may also exhibit willow-leaf patterns, crab-claw patterns, and ice-crackle designs, depending on glaze thickness and firing conditions.

4. Starlike Bubbles 

When viewed under a magnifying glass or held against the light, tiny bubbles can be seen scattered sparsely within the glaze, like stars at dawn. This poetic effect, known as “as rare as morning stars”, adds an almost cosmic beauty to the piece.

5. Sesame-Seed Support Marks

Ru ware’s most distinctive hallmark is its unique firing technique. To achieve a full glaze coverage, craftsmen used small conical clay supports during firing. After firing, these left behind tiny marks on the underside, resembling sesame seeds. This ingenious method preserved the integrity of the glaze while leaving behind a subtle trace of its craftsmanship.

These five defining features — the sky-blue glaze, jade-like texture, cicada-wing crackle (along with willow-leaf, crab-claw, and ice-crackle variations), starlike bubbles, and sesame-seed support marks — together embody the timeless charm of Ru ware. They reflect not only the Song dynasty’s pursuit of elegance and refinement but also the natural beauty that emerges from the unpredictable alchemy of clay, glaze, and fire. Each piece of Ru porcelain is truly one of a kind, a fusion of human artistry and the spirit of nature.