Different paper weights and types can be a bit confusing even for the experts who work within the paper and printing industries. In fact it has been said by some in the industry that “understanding paper weight is NOT common sense!” www.oki.com How much more confusing for the layman!
“80# text, 80# cover, 80# bond, gloss book, dull book, GSM, cardstock, parent, folio” The kinds and types of paper and paper measurement, not to mention paper coatings go on and on until one’s head is left spinning in multiple directions.
In this article we will attempt to give some general guidelines when it comes to paper weight, as well as define paper and printer terms that can be confusing, to say the least.
In the US paper weight is usually measured in pounds, while outside the US it is measured in grams. All of this began years ago, when rather than counting out 500 sheets (1 ream) of paper, sellers determined how many pounds the number of sheets equaled.
Another confusing factor is that different types of paper may have different weight standards. For example, newsprint that may be designated as 30# (based on the actual weight of 500 sheets of newsprint paper at its basic size of 24” x 36”) will actually be thinner than paper designated 20# copier paper.
Why? The latter is based on the actual weight of 500 sheets sized 17” x 22”. If you do the math you will discover the latter measurement cut in fourths will produce four 8.5 x 11 sheets, which is standard letter size paper.
ARE YOU CONFUSED YET?
It would be senseless to go on and try to explain all the details and nuances of paper size and weight. After all, will you remember those details the next time you need printing of any kind done? Not likely!
So, for the remainder of this article, we will attempt to highlight the most popular paper weights and their most common uses. We will also define a few other terms and coatings relating to paper and the printing industry.
Also known as writing paper, this is the most commonly used paper for everyday printing, as well as stationery and business letterheads. Bond paper varies in thickness from 16# up to 36#, the most commonly used being 20#. For general purposes this is the go-to paper.
Text paper is usually used by commercial printers to produce products such as brochures, fliers and other promotional products. It is also sometimes used for stationery, and generally comes in 60-130# weights. Upscale brochures will tend toward heavier weights and will most times use coating to both beautify and preserve the paper.
Book paper ranges from 30-115# and includes coated and uncoated papers. Commonly used for books, booklets, and magazines, the paper weight generally compares closely with text paper. The two terms are at times used interchangeably.
This paper is what is usually used for business cards, invitations, postcards, as well as covers for catalogs when a thicker, more durable cover is desired. This comes in weights from 60-120 #. Because of its popularity for cards it is also referred to as cardstock.
Paper Caliper Measurement
Sometimes you will encounter a paper measurement with the initials pts. This refers to paper that is measured using a caliper. Measurement of the paper is then shown in points, with one point equal to 1/1000 of an inch. This method is most commonly used to describe card stock thickness.
Paper without coating is highly susceptible not only to normal wear and tear, but fading because of exposure to light. While not as complicated as paper weights, this too can be a confusing subject. From liquid coatings all the way up to different kinds of film laminates, paper coating helps preserve your paper product. Let’s take a look at the most common ones.
Liquid Paper Coatings
This type of paper coating can be applied one of two ways; integrated in the printing process or after the print is completed. Some can be applied to certain areas of the printing project only. Photos or special print is many times highlighted with this method. The more durable liquid paper coating guards against wear and tear, and is often used on covers to minimize damage caused by handling. It also helps prevent smudging and keeps fingerprints from being as obvious, especially on darker backgrounds. Below we will look at the three most common coatings used in the printing industry.
This is a low cost water-based product that has high abrasion resistance, is shiny and smooth, and is one of the more environmentally friendly coatings. Due to its fast drying time it is at times preferred over some other coatings for a faster turnaround.
AQ is available in dull, gloss, or soft touch finishes, and unlike varnish coating is more difficult to apply only to spots on the printing project. It is usually applied to the entire sheet and is highly resistant to yellowing with time.
Aqueous Coating is applied in-line during the printing process. It is generally recommended for use on heavier paper such as cover stock since its use on thinner paper may cause wrinkling or curling.
Ultraviolet Coating gets its name from the finishing process that is used in its application. It is applied either in-line by printers or off-line after the printing process is done. It is applied as a liquid, then exposed to ultraviolet light to harden the coating. It is available in finishes such as high gloss, satin, and matte. It is also available in a variety of specialty finishes, for example different tints or with glitter.
UV coatings are slightly more apt to show fingerprints than AQ or varnish coatings, and some UV coatings can make paper more difficult to fold. Like AQ it is usually applied only to cover pages, or to heavier paper stock such as that used for postcards.
Like the other popular paper coatings, varnish coating is available in gloss, satin, or dull finishes. This option offers lower protection compared to the other two coatings mentioned here. However, it is widely used due to its low cost and ease of application. Just like ink, it is applied using one of the units integrated in the printing press. Varnish coating can either be flooded over the entire sheet or precisely to certain spots, providing highlighting where desired.
In conclusion, there are other coatings available as well, most of them falling under the heading of laminates. These coatings give varying degrees of protection to your product, and can vary widely in cost as well. When considering paper coating it’s wise to keep in mind the old adage, “You get what you pay for”. If your project is of first-class quality don’t skimp by using the cheapest possible coating, or worse yet no coating at all. Happy printing!