Everything Print Buyers Need to Know About Paper: Part One

This is part one of a two-part series.

The United States is second only to China in global paper production. In 2021, we produced 67.5 million metric tons of paper—with 8.3 million of that being graphic papers. As you'll see, there is so much that goes into the creation and selection of the paper you see and use every day. 

The paper industry is directly linked to the printing industry (for obvious reasons), so there is a lot you need to know about it. The knowledge shared in this guide will improve your planning process when you take on your next project. We've bolded important terms throughout this post—be sure to bookmark this page for reference!

Papermaking Basics

If you are fortunate enough to have been on a tour of a papermaking plant, you surely found it to be fascinating (and stinky). But most people don't get that chance, so we've outlined the process for you here.

A Brief History of Papermaking

While Chinese artisans began making paper as early as the 2nd century CE, production started in Europe in the 12th century. Paper was solely made in sheets until 1799 when Frenchman Louis Robert invented the Fourdrinier machine. It was later improved and patented in England by Henry and Sealy Fourdrinier, hence the name. The modern mechanical process of paper production results in large rolls of paper.

What Is Paper Made From?

All elementary school children learn that paper is made from trees. Specifically, softwoods like pine and spruce trees are used due to the strength and elasticity of their fibers once broken down. High-end papers are often partially or completely made from cotton fibers, making them more tear resistant.

The Papermaking Process

The first step when turning wood into paper is called pulping. This involves debarking logs, chipping them into small pieces, and then chemically pulping the chips. The chemical process is expensive but more efficient and produces higher quality paper. The other option is mechanical pulping, which yields a lower quality pulp. Pulping breaks down the lignin in the wood, resulting in a thick sludge.

Fun fact: Most papermaking plants filter and reuse the water used in the pulping process to reduce the environmental impact. They also use the bark and other byproducts to generate their own electricity!

The majority of the graphic papers made need to be white. Even if they will be off-white or have color added, the pulp must first be bleached. Another way papermakers have reduced their environmental impact is by switching from chlorine bleaching to oxygen bleaching. After washing and bleaching, the pulp is refined to increase the surface area and create better contact between the paper fibers. 

Next, the pulp sludge is sent to the Fourdrinier machine—a massive web of mesh screens that is 3.5 times an Olympic-size swimming pool and runs up to 56 miles per hour! There, excess water is vacuumed away and the sheet is passed over a series of heated iron cylinders for drying. The resulting dried sheet is starting to look like what we consider paper.

During the papermaking process, most fibers are oriented with their length parallel to the Fourdrinier machine. This is where the paper’s grain comes from. Paper folds and tears smoothly along with the grain, while cross-grain folds and tears are rough and cracked. This makes a difference when you're planning your job and even when you're putting paper into your copier!

After the Fourdrinier machine, the sheet runs through a series of giant reels during a process called calendering. For some low-quality paper, like newsprint, this is the end of the road. Higher quality papers go through additional finishing processes depending on the type of finish, color, and other attributes. One example is the use of clay coatings to produce shinier paper. The amount of calendering and amount and type of clay used delivers matte or glossy paper.

At this point, the paper is still on massive reels—not very helpful for presses, printers, copiers, or letter-writing! The reels are cut into smaller, but still very large, sheets. Sometimes the smaller sheets go through yet another series of finishing methods if they are destined to be specialty papers. When the process is finally completed, the large sheets are stacked on pallets and shipped around the world.

Paper Characteristics

As you've seen, the papermaking process is complex. Now imagine that same process times hundreds of different types, thicknesses, brightness levels, and colors. It's overwhelming! Some of the different characteristics of paper are detailed below.

Paper Types (Grades)

Paper types, also referred to as grades, are closely tied to their thickness and weight (which is explained below). Newsprint is its own category of very thin and unrefined paper. Bond and ledger paper stocks are typically thin and often used for writing. Index, bristol, and tag are very thick stocks and often of a lower quality. 

Most graphic papers can be grouped into text and cover stocks. Text stocks—referred to by their finishes as offset, opaque, matte, dull, gloss, etc.—are what you'd picture the inside of a book to be. Cover stocks are just that: uncoated and coated papers that could be used for a softcover book cover. 

Paper Thicknesses (Weights)

While thickness and weight are technically different measurements, graphic papers are most commonly referred to by their weights. Using the metric system, paper is categorized by the weight of one square meter. The measurement is grams per square meter, or g/m2.

In the United States, the basis weight of paper comes from how much a stack of 500 sheets weighs at its basic size—which varies for each of the types above. This is why our papers are categorized in pounds, represented by the # symbol. So, if 500 sheets of text paper at its basic size weighs 70 pounds, that paper is referred to as 70# text.

In the United States, some heavier cover stocks are measured in points. One point is equal to one thousandth of an inch (.001), so paper that is 0.01 inches thick is 10pt. It can add to the confusion around paper weights!

Paper Brightness and Opacity

How white is white? What we perceive as being "whiter" is actually a measure of brightness. It's measured on a scale of 1 to 100, with 100 being the brightest. Brighter paper means better contrast, more accurate color, and better readability. In short, it just looks better!

Opacity, on the other hand, is the measure of transparency. Completely opaque paper shows no print from the other side, but paper that is 0% opaque is completely transparent. If you plan to print on both sides of the paper, you need to pay close attention to the opacity of your paper.

Paper Finishes

All paper is categorized as either coated or uncoated. (Well, some stocks are coated on only one side and called "C1S," but most paper falls into these two categories.) Uncoated stock is rougher, absorbs ink better, does not smudge, and is better for writing on. It can be smooth or have a specific texture. A standard, smooth, uncoated stock is sometimes simply referred to as "opaque." 

Coated stock is sealed and therefore is very smooth. It has a sheen to it, and the coating makes it much harder to write on. Coated stock also does not absorb ink, so the printed dots sit on top of the paper and deliver a sharper image.

There are two basic subcategories within coated stocks: matte and gloss. Matte is shinier than uncoated paper but not super slick. Gloss has the thickest coating applied and is highly reflective, very slick, and very difficult to write on. It can also show fingerprints and reflect a glare from a light source.

Now that you know all about how paper is made and its different characteristics, stay tuned for part two of this post. We will discuss essential knowledge for planning your print projects and creating impressive works of art! 

Contact us today to get your project started.