Grade Layering
Multi-ply paperboard constructed with double-coated virgin chemical pulp on the top side and a white bleached chemical pulp back layer forms the standard substrate for luxury packaging applications. Within international trade classifications, gc1 folding boxboard provides high structural stiffness and pure white optical surfaces on both sides of the sheet. Middle plies contain bleached or mechanical pulp formulations optimized for high bulk and bending resistance.
Coating layers applied on modern web coater units deliver high smoothness for fine-screen offset lithography and gravure printing.
Optical Brightness
Double blade coating applied to the top liner creates a non-porous printing surface that minimizes ink vehicle absorption and enhances print contrast. High brightness across both surfaces allows gc1 folding boxboard to accept reverse-side printing for premium pharmaceutical cartons and cosmetics packaging without visual bleed-through. Pigment formulations incorporating calcium carbonate and kaolin clay yield excellent gloss retention after varnish application.
The bright white backing layer eliminates the dull gray or yellow appearance characteristic of recycled or unbleached kraft backings. Consistent ink acceptance across the sheet prevents mottle in large solid print areas.
Crease Endurance
Delamination resistance between individual plies prevents liner splitting when boards undergo sharp 180-degree folds during carton assembly. Internal bond strength of gc1 folding boxboard permits deep creasing scoring without sacrificing corner stiffness on automated filling lines. Score channels remain stable under ambient humidity changes.
