The Ultimate Guide to Paper Weight and Thickness for Printing
Paper weight and thickness play a crucial role in the printing industry, influencing the quality and functionality of various printed materials. From business cards to books, the choice of paper can make or break a project. Understanding paper weight and thickness is essential for both professionals and hobbyists to achieve the desired results in your printing endeavours.
This comprehensive guide delves into paper weights and thicknesses, covering everything from basic measurements to speciality papers. You will learn about GSM (grams per square meter), common paper types like bond paper and cover paper, and how to select the right paper weight for different projects. The article also explores the unique properties of speciality papers and provides practical advice for making informed decisions in various printing scenarios.
The Basics of Paper Weight Measurement
Understanding paper weight is crucial for anyone involved in printing or paper-related industries. Paper weight (gsm or lbs) is a measure of the paper’s density, which correlates with its thickness and durability. This section delves into the fundamental concepts of paper weight measurement, exploring different worldwide systems and standards.
GSM and Pounds – Paper explained
The two primary systems for measuring paper weight are GSM (grams per square meter) and pounds (lbs). GSM, as defined by ISO 536, is the standard used in most countries that follow ISO paper sizes. It represents the weight of a single square meter of paper. For instance, an A0 (841 x 1189mm / 33.1 x 46.8 in) sheet of 80gsm paper weighs exactly 80 grams, while a 100gsm A0 sheet weighs 100 grams.
On the other hand, the pound system is predominantly used in countries that employ US paper sizes, such as the United States and Canada, known as the basis weight. However, it’s important to note that the basis size varies depending on the paper type, which can lead to some confusion when comparing different paper weights.
Converting GSM to Pounds
Converting between GSM and pounds can be challenging due to the different calculation methods. For text paper, 1 lb equals approximately 1.48 GSM, while for cover paper, 1 lb is equivalent to about 2.708 GSM. This difference arises from the varying basis sizes used for different paper types.
To illustrate, standard office paper in the USA is typically 20lb Bond Letter Size, roughly equivalent to 75gsm paper. This is similar to the 80gsm A4 paper commonly used in Europe and other parts of the world. For those working with international printers, converting between these systems is often necessary to ensure the right paper weight is selected for a project.
International standards
The International Organization for Standardisation (ISO) has established global standards for measuring paper weight. ISO 536, titled “Paper and Board—Determination of Grammage,” defines grammage as grams per square meter (g/m²). This standard provides a consistent method for measuring paper weight across different countries and paper types.
The GSM system offers several advantages over the pound system. It provides a straightforward, apples-to-apples comparison between different paper types and weights. For example, a 250gsm sheet and a 100gsm sheet are both 1m² in size, but one is clearly heavier than the other. This simplicity makes it easier for professionals and consumers to understand and compare paper weights.
Understanding the weight measurement is essential for anyone working with paper or print materials. Whether using GSM or pounds, knowing how to interpret and convert between these systems can help you select the right paper for specific projects and ensure consistent quality across different paper types and international standards.
Paper Thickness and Its Importance
Paper thickness plays another crucial role in determining paper’s quality, durability, and suitability for various applications.
Micron measurement
Micron, expressed in points or thousandths of an mm, is the standard measure of paper thickness. One point equals 0.001 mm, so a 10-point paper is 0.001 mm thick. This precise measurement allows for accurate comparisons between different paper types and weights. Microns have a significant impact on the paper’s performance, affecting its flexibility, printability, and overall feel.
Bulk and density
Bulk and density are interrelated properties that influence paper thickness. Bulk refers to the volume per unit paper weight, typically measured in cm³/g. A paper with higher bulk has more volume and contains more air, resulting in a thicker sheet for a given weight. Conversely, density is the mass per unit volume, expressed in kg/m³. Papers with higher density are more compact and have lower bulk.
The relationship between bulk and density affects paper thickness. For instance, a 60 gsm paper with a bulk of 1.5 has a calliper thickness of 90 μm, while the same weight paper with a bulk of 2.0 has a thickness of 120 μm. This difference in thickness, despite identical weights, demonstrates the importance of considering both weight and bulk when selecting paper for your project.
Effect on print quality
Paper thickness does have an impact on print quality to some extent. Thicker papers can often absorb ink more evenly, leading to richer and more vibrant colour reproduction, which is especially crucial for high-quality prints like photographs and art reproductions. However, very thick papers may require special handling in certain printers and could impact the overall print speed.
Coated papers, which are often thinner but denser, can provide excellent print quality due to their smooth surface. These papers allow for sharper text and more detailed images, making them ideal for magazines and brochures.
Coated paper vs uncoated paper
Coated papers features a surface layer that enhances its properties, such as weight, gloss, or smoothness. This coating reduces ink absorbency, producing more vibrant colours and sharper details. Uncoated paper, on the other hand, has no additional surface treatment and behaves more like a sponge, absorbing more ink.
Coated papers are generally less bulky and thinner than uncoated papers of the same weight. For example, a coated paper may feel thinner and more compact than an uncoated paper of the same GSM. This difference in thickness and texture can influence the perceived quality and suitability for different print projects.
Weight vs Thickness
While paper weight and thickness are related, they are not always directly proportional. Factors such as fibre composition, manufacturing processes, and coatings can result in papers of the same weight having different thicknesses. For instance, a 250 gsm coated paper may be thinner than a 200 gsm uncoated paper due to differences in density and bulk.
For example, a thicker paper may be preferred for business cards to convey a sense of quality, while a thinner, high-weight paper might be more suitable for a premium magazine.
Common Paper Weights and Their Uses
Understanding paper weight is crucial for selecting the right paper for various applications. Different weights serve distinct purposes, from lightweight papers for everyday printing to heavyweight options for premium projects.
Lightweight papers (under 80 GSM)
Lightweight papers, typically under 80 GSM, are ideal for specific applications where thin, delicate sheets are required. Bible paper, for instance, is an ultra-thin, high-opacity paper designed to reduce the bulk of large books. These papers are also commonly used for dictionaries, encyclopedias, and other reference materials where a large number of pages need to be bound together without creating an excessively thick volume.
Mediumweight papers (80-120 GSM)
Mediumweight papers, ranging from 80 to 120 GSM, are versatile and widely used for various purposes. Standard copy paper, typically 80 GSM, is perfect for everyday printing and document reproduction, often found in most printed books. This weight suits internal memos, drafts and general office use. Slightly heavier options, such as 90 GSM paper, offer a slight upgrade in texture and durability, making them ideal for business correspondence, reports, and proposals.
For more substantial documents, 105-120 GSM papers provide a sturdier feel. These weights are suitable for professional documents like resumes and letterheads that require a touch of substance. These weights are also commonly used for textbooks, flyers, and brochures, offering a good balance between quality and cost-effectiveness.
Medium to heavyweight papers (120-170GSM)
Medium to heavyweight papers in the 120-170 GSM range offers superior thickness and opacity, making them perfect for high-quality full-colour printing with minimal show-through. These papers are ideal for company brochures, detailed catalogues, and premium magazines. The 150 GSM weight, for example, is often the go-to choice for luxurious prints, high-end publications, and quality flyers where image quality and touch are paramount.
Photobooks and booklets frequently use papers in this weight range to ensure durability and a premium feel. The increased thickness allows for better colour reproduction and image clarity, enhancing the overall quality of the final product.
Heavyweight papers (170-250 GSM)
Heavyweight papers, ranging from 170 to 250 GSM, are designed for applications that require durability and a substantial feel. These weights are commonly used for book covers, hardback photobooks, and high-quality business brochures. The 240 GSM weight is a versatile cardstock that works well for the covers of booklets and catalogues, providing a sturdy base for embossing and other special post-printing effects.
Papers in the 240-270 GSM range are ideal for top-end business cards, invitation cards, premium magazine covers, and sturdy promotional postcards. These weights convey luxury and are thick enough to feel substantial while maintaining flexibility.
Card papers (250+ GSM)
Card papers, typically 250 GSM and above, are used for applications that demand maximum durability and rigidity. These heavyweight options are perfect for packaging materials, business cards, and other items that must withstand frequent handling such as childrens books for toddlers.
The 290 GSM weight, for example, is often used for heavyweight business cards, invitations, and announcement cards, providing a substantial backdrop for vibrant colours and detailed graphics. Even heavier weights, such as 330 GSM and 350 GSM, are excellent for creating premium book covers, heavyweight photo prints, and high-end, stand-alone displays.
For the most luxurious applications, papers weighing 400 GSM and beyond enter the realm of board stock. These ultra-heavy weights are commonly used for hardcover bookbinding, packaging solutions, and high-quality mounting boards, offering rigidity and weight for projects requiring maximum strength and protection.
Specialty Papers and Their Unique Properties
Speciality papers offer a unique experience that engages the senses in a way smooth paper cannot. These papers are designed to enhance the visual appeal and add physical depth to products, making them stand out. With their distinct feel and appearance, speciality papers have become a favourite in luxury markets, often used in high-end packaging, bespoke invitations, and premium branding materials.
Coated vs uncoated papers
Coated and uncoated papers each have their own set of characteristics that make them suitable for different applications. Coated papers have a layer of coating, typically clay applied to their surface. This coating restricts the amount of ink absorbed into the paper, allowing it to sit on top, resulting in crisp, defined dots. Coated papers are categorized by their finish: gloss, silk, or matte. They offer excellent ink holdout and perform well with areas of heavy solid colour and special metallic inks.
Uncoated papers, on the other hand, lack this coating and are more porous. The ink soaks into the paper, giving it a softer, warmer appearance. Uncoated papers have an inherent warmth, making them well-suited for projects in educational, non-profit, and environmental sectors such as books and board reports.
Textured papers
Textured papers feature a raised, uneven surface. These papers come in various styles, each with its unique feel and aesthetic appeal. Some common texture types include:
- Arlin: Features a distinct, finely embossed surface with a subtle wave-like pattern.
- Linen: Mimics the look and feel of linen cloth with a subtle, consistent crosshatch pattern.
- Laid: Known for its handcrafted appearance with parallel lines.
- Felt: Possesses a softer, more organic feel with a gentle, tactile pattern.
- Embossed: Involves raising or depressing patterns onto the paper surface for a three-dimensional effect.
Textured papers are often used in luxury packaging, high-quality brochures, premium invitations and hardback book covers.
Recycled and eco-friendly options
As sustainability becomes increasingly important, many businesses are turning to recycled and eco-friendly paper options. These alternatives help reduce waste and pollution while creating beautiful and impactful products. Some eco-friendly paper options include:
- Hemp paper: Made from hemp, a regenerative crop that grows rapidly and requires fewer chemicals, water, and energy to turn into pulp. Hemp paper is versatile and can be used for various products, from business cards to packaging solutions.
- Recycled cotton paper: Made from recycled cotton textile scraps such as t-shirts or jeans. It has a soft, subtle texture and is ideal for business cards and unique packaging solutions.
- Straw-based paper: Made by reclaiming scrapped straw and wheat, eliminating the need for burning crops. The production of straw paper requires 25% less water and 70% less energy than traditional paper.
- Bamboo paper: Made from bamboo, an extremely fast-growing grass. It typically has a soft, subtle watercolour-like texture and a smooth off-white shade.
- Sugarcane (bagasse) paper: Made from agricultural fibre waste called bagasse. It looks, performs, and feels just like paper while being chlorine and acid-free and completely recyclable.
These eco-friendly optionshelp reduce the paper industry’s impact on the planet and offer unique textures and finishes. You can create distinctive products by choosing these alternatives while demonstrating their commitment to sustainability.
Selecting Paper Weight for Different Print Projects
The choice of paper weight can transform a simple brochure into compelling marketing material, endorsing professionalism without saying a word. Whether piecing together a high-end portfolio, a corporate report, or promotional booklets, the paper weight chosen can either uplift or undermine the product’s perceived value.
Business Cards
When it comes to business cards, the paper weight plays a vital role in creating a lasting impression. The ideal paper weight for business cards typically falls between 300 and 400 GSM. These weights provide a balance between durability and a premium feel. For those seeking a more luxurious option,450 GSM uncoated cardstock offers a premium look while maintaining budget-friendly prices.
Heavier-weighted cards generally represent higher quality, ensuring durability and leaving a positive impression on prospective customers. They are more resistant to wear and tear, making them ideal for long-lasting use. For instance, 14pt cardstock offers a balance between durability and affordability, while 16pt cardstock adds a touch of luxury while remaining budget-friendly.
Marketing Materials
For marketing materials such as brochures, flyers, and booklets, the choice of paper weight depends on the specific requirements of the project. Text paper weights ranging from 115 GSM lb to 150 GSM are commonly used for these materials. 115 GSM paper is commonly used for catalogues with high page counts, as its lower cost helps keep printing expenses down while still providing a professional look.
For more substantial marketing materials, 150 GSM paper is a great choice, offering a sturdier and more premium feel, though it comes at a higher price point. If you’re printing a booklet, you might consider using 115 GSM paper for the internal pages and 150 GSM for the cover. This combination gives you a durable cover while maintaining a good balance between quality and cost for the internal pages.
Cover paper for books typically ranges between 250 to 350 GSM, providing a durable and sturdy feel. This weight not only enhances the book’s overall structure but also helps prevent the internal pages from bending or shifting, ensuring a professional and polished appearance.
Packaging and Labels
For packaging and labels, the choice of paper weight is crucial for both esthetics and functionality. Label paper typically ranges from 80 to 130 GSM, with a specific weight depending on the product type and the desired effect. For packaging materials, heavier weights of 250 GSM and above are often used to ensure durability and protection.
When selecting paper weight for labels, it’s essential to consider the type of surface the label will be applied to. For instance, a marked natural or cotton paper, among the heaviest in the catalogue, can give a product a premium and elegant touch, making it particularly suitable for creating high-quality labels.
Book Papers
For book printing, the choice of paper weight varies depending on the type of book and its intended use. For novels and text-heavy books, lighter weights such as 70 to 90 GSM text stock are often used. This weight is similar to standard copy paper and is ideal for books with high page counts.
For children’s books, coffee table books, or art books, heavier weights like 150 to 170 GSM are preferred. These weights provide superior thickness and opacity, ensuring minimal show-through and allowing for high-quality full-color printing.
By understanding the characteristics and applications of different paper weights, one can make informed choices that enhance the overall impact of their print projects.
Conclusion
Paper weight and thickness significantly impact the quality and functionality of printed materials. From lightweight papers for everyday use to heavyweight options for premium projects, understanding these factors is crucial to selecting the right paper for specific needs. The diverse range of paper weights and thicknesses available provides opportunities to create unique and impactful print products catering to various industries and applications.
To wrap up, the choice of paper weight and thickness goes beyond mere technical specifications. It has the power to enhance the overall user experience, conveying quality and professionalism without words. As the printing industry continues to evolve, staying informed about paper properties and their applications is essential to make well-informed decisions and produce high-quality print materials that stand out in a competitive market.
FAQs
- What are the typical uses for 80 GSM paper? 80 GSM paper, also known as text paper, is frequently used in commercial printing. Common applications include brochures, letterheads, stationery, internal memos, and thesis papers.
- Which is thicker: 70 GSM paper or 115 GSM paper? This depends on the type of paper as weight is not the sole factor in thickness. An uncoated 70gsm bookwove paper will more than likely be thicker than a 115 GSM coated paper.
- What is the difference between GSM and microns? GSM (grams per square meter) measures the weight of paper, while microns measure its thickness. A higher GSM often indicates thicker, heavier paper, but different types of paper (e.g., coated vs. uncoated) can vary in thickness even at the same GSM.
- Is heavier paper always better for printing? Not necessarily. Heavier paper (with a higher GSM) is sturdier and often gives a more premium feel, making it ideal for business cards, covers, and high-end brochures. However, for projects with many pages, such as booklets or magazines, lighter paper may be preferable to avoid bulk and reduce printing costs.
- Can all printers handle heavier paper weights? Not all printers are designed to handle heavier paper weights. Papers above 170 GSM may require a specialised printer with the capability to feed thicker stock without jamming.
