Damage Prohibition: Products with breakage, cracking, chipping or scratch-causing sharp edges are rejected unconditionally.
Shape Requirement: No deformation, unevenness or skew allowed for product mouths and bottoms.
Material & Color Standard:
Clear glass: 100% virgin material; must be transparent, bright white, free of discoloration.
Colored glass: Color tone to be stable, pure and fully uniform.
Thickness Uniformity: Consistent wall thickness required for both hand-blown and machine-blown products; no side-to-side thickness variation.
Melt Quality: Glass material to be fully and uniformly melted. Strictly minimize defects including stones (unfused slag), streaks and air bubbles.
Bubble Limit (excluding bubble-effect glass):
No bubbles permitted within 1cm from the product mouth.
Below the mouth: Max 2 bubbles (diameter >2mm) OR max 3 bubbles (diameter >1mm); clustered bubbles are not allowed.
