pecifications for offset paper

The specifications for offset paper can be found in the national standard GB147 “Dimensions of Base Paper for Printing, Writing, and Drawing.” Size deviations and skew must not exceed ±3mm. Offset paper comes in various grammages, with commonly used weights being 60, 70, 80, 90, 120, 150, 180, 200, and 250g/m². Offset paper for printed books and periodicals is typically below 90 g/m², while covers range from approximately 70 to 200 g/m². Offset paper features stiffness and smoothness, making it easy to bind and process.

① Any method used for collating pages achieves a clean and orderly result.

② Any folder can produce excellent folding results, with special suitability for high-speed folding. ③ For offset paper publications, designs should primarily use three or fewer folds (never four folds). Ideally, use two folds (for paper over 80 g/m²) followed by gathering. Due to its thickness and high basis weight, excessive folding can cause “eight-shaped” creases or stubborn folds that resist flattening within the signatures. This leads to uneven trim edges and warped bookblocks after cutting.