- Publishing & printing
Ed #12 Standards
Ed™ knows standards. You’ve always been able to count on Ed. Now you can count with him too. Whether it’s laying out a brochure, putting together a budget or specifying color, the graphic arts, like virtually every profession, depends on numbers to convey information, make comparisons and get the job done.
That’s where this issue of Ed comes in. It looks at many of the standards developed for paper and printing, examines where they came from, and describes how you can apply them to make your work more efficient and effective. The goal is to give you an Ed that you’ll always want to keep around—and turn to for answers.
We want you to feel the same way about Billerud. We love paper and printing—and we want to provide the tools that designers, printers and other graphic arts professionals need: To communicate well. To set new standards of creativity and quality. To move their audiences.
Ed will never grow old, but some of the information in this issue is out of date.
Measuring up. In the graphic arts, as in many other fields, success means doing it by the numbers. Lots and lots of numbers.
Mathematicians and bakers, sales people and sailors, card counters and accountants, designers and printers, all share a common interest.
Numbers—mathematics—are the world’s only universal language, understood across nations and cultures, and they play a part in virtually all human activities. With numbers, we explore the mysteries of the universe and bake cakes that serve eight; we calculate commissions and chart a course. We gain the ability to set common standards. We make better decisions. We live better lives.
Units of measurement were some of the earliest tools that humans developed—sophisticated systems were in use more than 5,000 years ago—and are still in use by their descendants today.
Most traditional measurement standards are based on the human body. One of the first, the Egyptian cubit, was the length of the arm from the elbow to the extended fingertips. Of course, the length of the cubit varied according to the length of each person’s arm. To correct for the differences, the Egyptians established the Royal cubit, which sounds like it might belong in the next Indiana Jones movie. Actually, it was simply a black granite rod that everyone could use to standardize their own measuring rods.
The human body was the standard for many other measurements too. The inch was first defined as the width of a thumb. The foot began as the length of a human foot, although it has since grown to be longer than the average size. The yard was defined as the distance from the tip of the nose to end of the middle finger of the outstretched hand. If you stretch both arms out to the side, you will have a fathom, or six feet.
Other common measurements grew out of human activities. An acre, or 43,560 square feet, was originally the amount of land that could be plowed by a team of oxen in a single day. (Actually, in half a day, since the oxen needed to be fed and rested in the afternoon.) The mile was the distance traveled by a Roman legion in 1,000 paces. Ancient Egyptians and Greeks used a wheat seed as the smallest unit of weight, while Arabs measured the weight of small objects with carob seeds, which gave jewelers the term “carat.”
While the first decimal measurement systems were used as early as the Bronze Age, they only began to achieve widespread use in the late 1700s in France. In 1793, the national government under Napoleon adopted the metric system, with a meter established as one ten-millionth of the distance from the North Pole to the Equator when measured on a straight line along the surface of the earth through Paris. All units were in multiples of 10, and area, volume, liquid capacity and weight measures were interrelated.
Wars, national pride, tradition and the desire for more exacting standards all helped to slow the adoption of a truly global metric system. (For the sake of absolute consistency, the meter is now defined as the distance light travels in a vacuum in 1/299,792,458th of a second.) In North America, where people combined the measuring systems brought from their homelands, standards for such measurements as gallons and tons came to differ from the “Imperial” measures used in Great Britain.
Numbers have played a role in the graphic arts from the very beginning. In fact, the Gutenberg Bible, which appeared in 1454, is usually described as the 42-line Bible (B-42) because that is the number of lines found on most of its pages. The lines are laid out using a two-column grid and what became known as a Textura typeface, right justified, with the printed area measuring 292 mm x 198 mm.
The first standard paper sizes are even older than the Gutenberg Bible. A marble tablet inscribed with the outlines of four sizes of paper (no, they weren’t labeled short, tall, grande and venti) was placed in a public square in Bologna, Italy, in 1398, to serve as a guide for the paper manufactured in the region. Then and now, one of the key factors in establishing paper sizes is the number of times sheets can be folded to form the pages of a brochure or book. Books made from a once-folded sheet of paper are called folio editions, while quarto editions are bound from twice-folded signatures. The traditional English “Pot” size, which measures 12 3/4” x 15 1/2”, folds into a quarto size of 6 3/8” x 7 3/4”; large “Elephant” sheets, which measure 23” x 28”, fold into 11 1/2” x 14” quartos.
Today, most paper sold in the United States, Canada, and a few other countries is measured in inches. The basic sheet size, recognized by the American National Standards Institute (ANSI), is the ANSI E size, which measures 34” x 44”. Although no one knows for sure how this size came to be the standard, some say it stems from the size of the equipment that was used when paper was made by hand. Fiber and water slurry were passed through a screen at the bottom of a box that was 17” deep and 44” wide, which was as far as the papermaker could comfortably stretch his arms. The sheet of paper that was produced, folded in half in the long direction and then twice in the opposite direction resulted in a sheet of paper that measured 8.5” x 11”.
Larger ANSI sizes are based on printing a number of 8.5” x 11” sheets with a minimum of waste. The next largest size—the ANSI B sheet—also known as ledger or tabloid size, measures 11” x 17”, which is exactly twice as large as 8.5” x 11”. Other sheet sizes are also based on the 8.5” x 11” standard, but are slightly oversized to accommodate color bars, trimming, gripper edges, and other printing requirements. For example, a 23” x 35” sheet yields 16-8.5” x 11” pages when it is trimmed after printing.
Papers manufactured outside North America are typically produced using International Organization for Standardization (ISO) sizes. ISO sizes are based on a sheet of paper measuring one square meter, known as the AO size, although it is not one meter square. AO sheets measure 841 mm x 1189 mm (or 33.1” x 46.8”), a proportion, or aspect ratio, that is based on the square root of two. This ratio is used because a sheet with the aspect ratio of the square root of two can be divided parallel to its shortest side into two equal halves that will also have the aspect ratio of the square root of two. Successive papers in the series—A1, A2, A3, A4 and so on—are each half the size of the preceding paper size, measured by its shorter side.
Because the ISO sizes always have the same proportion, images can be scaled up or down to fit on different sizes of paper without cropping the image differently. An image on an A3 sheet, for example, can be scaled down to fit an A4 sheet. By the same token, brochures can be made by using the next larger size; for example, an A3 folded once will produce an A4 size brochure.
The most frequently used ISO paper size is the A4 size, which measures 210 mm x 297 mm (or 8.3” x 11.7”). There also are B standard sheets, which are used most frequently for posters and books, and C series papers that are only used for envelopes.
In addition to size, you also need to consider a paper’s weight.
In North America, printing papers are usually classified by basis weight, which is the weight in lbs. of a ream of paper (500 sheets) in the basic size of that grade. That’s where things can begin to get complicated. Basic sizes are usually not the size of the finished, printed, sheet of paper, but rather the size of the sheet from which the finished paper is cut. So if you buy a 70 lb. paper for use in an 8.5” x 11” brochure, for example, it does not mean that 500 sheets of the 8.5” x 11” paper weigh 70 lbs. Rather, the 70 lb. weight refers to 500 sheets of the basic 25” x 38” sheet size from which the smaller sheets were cut.
To make things more complex, basic sizes are not the same for all grades of paper. Book papers, including coated text and offset papers have a basic size of 25” x 38”. The basic size of bond and ledger writing papers, 17” x 22”, allows for four 8.5” x 11” sheets. Coated and uncoated cover papers have a basic size of 20” x 26”, and other papers have other basic sizes.
Because of these variations in size, papers that have the same basis weights may not look and feel the same. A sheet of 70 lb. text stock, for example, will feel and look much lighter than a sheet of 70 lb. cover. To make things more complicated still, size and weight tables and price lists usually do not refer to a 500 sheet ream, but to the paper’s “M” weight, which is the weight in lbs. of 1,000 cut sheets of the paper. The ISO standards that are widely used outside North America rely on a different measuring system. Basis weights are expressed in grammage, or the weight in grams of one square meter (g/m2 or gsm) of the paper, regardless of its grade or finished size.
Paper weight is important because it helps to determine the project’s quality and feel, the type of presses used and the project’s costs. Almost always, heavier weight papers feel richer and more luxurious than their lighter weight counterparts and can stand up better to the handling they might receive in the mail. Heavier weight papers can also carry more ink as well as varnishes and other coatings. Print show-through is virtually eliminated.
The weight of the paper also comes into play when determining the type of press to be used. To accommodate their high speeds, web presses typically must use lighter weight stocks—50 lb. basis weights or less—and rarely can print anything heavier than a 100 lb. coated, or 80 lb. uncoated cover. Although they run more slowly than most web presses, sheetfed presses can handle heavier weights of paper and a wider variety of textures. Digital presses usually fall somewhere in the middle, with some models able to handle anything from 16 lb. bond up to a 130 lb. cover.
Sometimes, you also need to consider the thickness of the paper—its caliper. A paper’s caliper is usually expressed in points, with each point (pt.) equaling .001”, so an 8 pt. stock, for example, would be .008” thick.
Caliper is an important measurement when you are working with card stocks to produce business cards or direct mail materials. The higher the number of points, the thicker—and stiffer—the card will be.
Another related measurement is bulk, which is important in book publishing because the bulk of the paper determines the thickness of the book. Bulk is expressed as pages per inch (ppi).
While it may seem logical to think that a paper with a heavier basis weight will also have a larger caliper and bulk, that is not always the case. A paper’s finish also affects both measurements. Coated papers will have a lower caliper and bulk than an uncoated paper of the same basis weight. Cover stocks are usually twice the thickness of text papers with the same basis weight.
Sheet size, basis weight, caliper and brightness are just a few of the numbers encountered in printing. Others include the points and picas used in typesetting.
In typesetting, points (pts.) are used to measure the height of type and the vertical distance, or leading, between lines of type. There are 72 pts. to the inch, which means that standard 8 pt. type is 1/9th of an inch tall.
Although they are sometimes measured in inches or millimeters, the length of lines of type, column widths and margins are traditionally measured in picas. There are 12 pts. in a pica (and approximately six picas to the inch). So if you want to know how much vertical space a 48 pt. headline occupies, all you need to do is divide 48 by 12 to arrive at four picas of vertical space.
Just as designers and printers need standard references for type, they also need standard references for color. That’s where the Pantone Matching System,® the Toyo Ink System and other color matching systems come in.
In the same way that preschoolers mix yellow and blue finger paint to create green, color matching systems typically use a limited number of basic colors to create hundreds of solid, or spot colors, each identified by a number. Swatchbooks show small samples of each color on coated and uncoated papers, typically in both matte or gloss finishes, along with the formula used to create the color. Printers typically order the color by its number or mix it themselves according to the formula found in a guide. By using these standards, designers, printers and others can specify, match and reproduce colors, regardless of the specific equipment used to reproduce them. You could call printers around the world and ask for Pantone 200, for example and in theory at least, the reds they produce would all be identical.
Screen rules come into play in a large majority of commercial printing projects. Photos and artwork typically are printed using halftone screens, which produce a grid of dots that are opaque and distinct from one another. The size of the dots is determined by the number of lines per inch (lpi) or, in digital printing, dots per inch (dpi), with higher numbers representing finer screens that will capture subtler shifts in tone and more detail. Most commercial printing today relies on 150 to 175 line screens.
Not all images are printed using halftone screens, however. Some projects rely on stochastic screening techniques in which images are reproduced using microdots of the same size with random spacing between the dots or with variably sized dots and random spacing. Either way, the dots used are quite small and measured in microns or millionths of a meter. While a typical period at the end of a sentence is around 615 microns, the stochastic dots used to produce images typically measure around 20 microns, which is about the same size as a mold spore. In addition to microns digital prepress and print production techniques have spawned another set of numbers that designers should know.
As discussed in Ed #10, the most basic element in digitized images is the bitmap, also known as a pixel, an abbreviation of “picture element.” Pixels are tiny black and white or colored squares that are arranged together like tiny mosaic tiles to form images. When an image is scanned or captured by a digital camera, the number of pixels that are captured (measured by pixels per inch or ppi) determines the resolution of the image, and the number of pixels contained in the original image cannot be increased. The greater the number of pixels, the higher the resolution of the image, and the more computer storage space it requires.
While modern prepress techniques can work wonders, they can’t do much to rescue a low resolution image captured with your cell phone camera. To successfully print a 150 line screen, the rule of thumb is that you should begin with resolution of at least 300 ppi. Higher screen rulings or stochastic printing might require a higher resolution.
“I wish he may not give himself airs—a sealed envelope, forsooth.” Patrick O’Brian
The desire to protect—and conceal the contents of—written communications while they are being delivered is as old as written communication itself. Archeologists know that the clay tablets used for cuneiform writing in ancient Babylonia were sometimes wrapped in a clay covering that would have to be broken before the recipient could read the message hidden beneath.
While paper may have been used to wrap messages in ancient China, the first envelopes as we know them appeared in Europe in the 17th century. Like all envelopes made before the mid-19th century, they were made by hand, usually by cutting a diamond-shaped piece of paper that could be folded over the message and sealed at a single point with wax.
For many years, envelopes were made from any paper that came to hand. During the American Civil War, when the Confederate states faced severe paper shortages, “austerity covers” were crafted from the backs of ledger sheets, blank pages in books, used envelopes that were turned inside out, and even wallpaper torn from walls.
Today, an estimated 450 billion envelopes are made each year. Some are made from synthetic materials, such as polyethylene. Others are made from manila, a fiber from the leaves of a plant in the Philippines that produces a strong, yellowish paper. However, most envelopes are made from paper cut into a blank that is the shape of the envelope with its flaps opened and laid flat. A strong glue is applied to the flaps that hold the envelope together, and a weaker glue is applied to the flap that will be sealed by the user. Then the paper is automatically folded into its final shape.
Envelopes are available in hundreds, if not thousands, of varieties and sizes. Pocket envelopes have the flap on the short side, while those with the closing flap on the long side are sometimes referred to as standard or wallet style envelopes. Single and double window envelopes, which are most often used for bills, help the sender save money by eliminating the need to address the envelope or write the return address. Open window envelopes, which do away with the translucent plastic cover, are more environmentally friendly but less secure.
Envelopes, like paper, are measured to both ANSI and ISO standards, and there are sizes and shapes for virtually every purpose. But they are not all the same in terms of postal regulations. In the U.S., for example, square envelopes usually have higher postal rates than their rectangular counterparts because the square envelopes cannot be sorted using automated equipment and must be canceled by hand.
Automated sorting systems impose other requirements on envelopes, too. Addresses and other information must be formatted properly to facilitate processing by optical character recognition equipment. Simple fonts, such as Arial or Helvetica, 12 pts. or larger, are least likely to confuse automated systems. It’s also important to avoid using any graphics in the address zone. The United States Postal Service’s (USPS) Domestic Mail Manual is more than 1,800 pages long and contains explicit mailing standards for virtually every type of card, letter, brochure, catalog, poster, magazine, book and package. It would take far more room than Ed has to begin to summarize all of the rules, but fortunately, the USPS offers a number of tools to help designers and others ensure that their projects meet the right standards.
The Mailpiece Quality Control (MQC) Program offers a self study course that leads to certification in “mailpiece” design. Design templates for business reply cards and other communications provide USPS approved layouts so all you need to do is insert your address and permit numbers. Specially trained Mailpiece Design Analysts (MDAs) provide assistance on design and test paper and samples for acceptable thickness, background color, flexibility, rigidity and barcode print tolerances.
Business reply cards (when the permit holder pays postage), courtesy reply mail (when the sender pays the postage), and postcards qualifying for low cost automation rates need to meet specific design standards. In the United States, the standards include the use of a delivery point bar code or ZIP + 4 code. Addresses must be printed using dark, nonmetallic inks and cannot be skewed more than 5 degrees from the bottom edge of the piece. Business reply and courtesy reply cards require a permit number supplied by the USPS.
Because standards are stringent, the USPS suggests submitting designs to a Mailpiece Design Analyst before the design is printed.