What does crazing mean?
Crazing is the formation of a fine network of hairline cracks on the surface of a material, most familiarly in the glossy glaze of ceramics but also in paints, varnishes, glass, and certain plastics. It arises when the outer layer shrinks or expands at a different rate than the body beneath it — through firing, cooling, moisture absorption, or simple age — producing a delicate web of intersecting lines. Far from being merely damage, crazing occupies a curious place between flaw and feature: collectors often prize the soft, aged patina it lends antique porcelain, and historical Chinese kilns famously cultivated deliberate crackle effects with evocative names. In conservation and materials science, however, crazing signals deterioration and can compromise an object's integrity over time. The word also has technical use in polymer science, where it describes localized deformation zones preceding fracture.
nounA network of fine cracks that appears on the surface of a material such as ceramic glaze, paint, or glass, typically caused by shrinkage, stress, or exposure to heat and moisture.
- A network of fine surface cracks in ceramic glaze, often valued aesthetically in pottery.
- Similar fine cracking that develops in paint, varnish, glass, or other coatings due to aging, stress, or environmental conditions.
"The collector admired the delicate crazing on the antique bowl, a sign of its age rather than a flaw."
"Years of temperature fluctuation caused fine crazing across the teapot's celadon glaze."
"The old varnish showed extensive crazing where sunlight had hit the tabletop."
Rarely pluralized; usually treated as an uncountable mass noun describing the phenomenon collectively.
"Different sections of the vessel showed distinct crazings, each with its own pattern."
In ceramics, crazing isn't always a defect — Chinese potters prized it so highly they deliberately created it and gave it names like 'cracked ice.'
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of crazing
Crazing derives from the verb 'craze,' which entered English from Middle English 'crasen,' meaning to shatter or break, likely of Scandinavian origin (compare Old Norse). Originally referring to violent breaking, the sense gradually narrowed and softened over the centuries; by the seventeenth century 'craze' could mean to weaken or impair, and the noun 'crazing' came to describe fine surface cracking specifically, particularly in glazed ceramics. Related words include 'crazy' and 'crackle,' though the latter has a distinct Germanic root.
How crazing is actually used
Most commonly used in ceramics, antiques, and conservation contexts. In pottery, crazing is often considered an aesthetic feature rather than a defect. Also appears in materials science describing similar phenomena in polymers.
Easily confused with crazing
Crazing refers to a fine, web-like network of surface micro-cracks (especially in glaze or paint), while cracking describes larger, deeper structural fractures.