Offset Paper vs. Copy Paper: What's the Difference?

Introduction

Offset paper and copy paper are both common types of paper, but they are often confused with each other. Did you know that they have significant differences? Using the wrong type of paper for a specific purpose can affect print quality. In this article, we’ll explain the key differences between offset paper and copy paper so you can choose the right one for your needs.

Key Differences Between Offset Paper and Copy Paper

Moisture Content

One major difference between these two types of paper is their moisture content.

Offset paper has a higher moisture content (6-8%) to prevent shrinkage during printing, ensuring proper alignment of colors and text.

Copy paper, on the other hand, has a lower moisture content (3.8-5%) to prevent curling when exposed to the high heat and pressure of laser printers and copiers.

Using paper with too much moisture in copiers can cause wrinkling, while paper with too little moisture in printing presses may shrink and cause misalignment.

Static Control

Copy paper is specially treated to reduce static electricity.

During production, an anti-static agent is applied to prevent paper sheets from sticking together.

Special static removal devices are used when cutting the paper to further eliminate static buildup.

This ensures smooth feeding in copiers and printers, reducing paper jams and improving efficiency. Offset paper, however, does not require this treatment since it is used in traditional printing presses.

Surface Treatment

The surface finish of offset paper and copy paper differs based on their intended use.

Offset paper has a smoother surface to meet printing requirements. It undergoes hard calendering, which increases its smoothness and improves print quality.

Copy paper needs to maintain a balance between smoothness and stiffness. It undergoes soft calendering, which keeps the surface slightly rough. This enhances paper stiffness and bulkiness, allowing for better feeding and reduced jamming in office printers.

Whiteness

Copy paper is whiter than offset paper due to its higher brightness levels.

Copy paper typically has a brightness level of 102%-104% or even 108%-110%, achieved by adding optical brightening agents (OBAs) during production.

Offset paper has a lower brightness level, usually 96%-102%, because high whiteness is not as crucial for printing applications.

Applications

The usage of copy paper and offset paper differs significantly.

Copy paper is used for everyday office printing and copying. A4 copy paper is commonly used for documents, promotional materials, and contracts. A5 copy paper is often used for name tags, table signs, and small cards. Offset paper is used mainly for publishing and commercial printing, and its weight determines its application.

Lightweight offset paper is ideal for Bible printing and pharmaceutical instruction leaflets.

Heavier offset paper is used for book covers, magazines, inserts, manuals, posters, maps, brochures, labels, and packaging materials.

Conclusion

Now that you understand the differences between offset paper and copy paper, you can make the right choice for your specific needs. If you're looking for high-quality paper for printing, copying, or publishing, feel free to contact Golden Paper. We provide professional service and customized solutions to meet your requirements!