An Introduction to Offset Paper

Offset paper is classified into Special Grade, Grade 1, Grade 2, and Grade 3 based on pulp composition, offering high strength and printability. It comes in single-sided and double-sided varieties, with two grades: supercalendered and standard calendered. Offset paper is a premium grade for book and magazine printing, demanding high contrast, dimensional stability, and surface strength. Its pH should be near neutral or slightly alkaline to prevent adverse effects on printed materials.

Offset paper exhibits minimal dimensional change, uniform ink absorption, excellent smoothness, dense opacity, high whiteness, and strong water resistance. It requires film-forming offset inks and high-quality letterpress inks. Ink viscosity should not be excessively high, as this may cause powder shedding or hairline cracks. Preventing back-side soiling is also crucial, typically achieved through anti-soiling agents, powder spraying, or interleaving paper.