2) Dot gain
3) Grain direction
4) Colored paper
5) Cover or text weight
6) Sheet size
7) Basis Weight
9) Paper dummies
Dot gain occurs when the ink dot spreads slightly on the sheet. Many things can affect dot gain: paper surface; viscosity and temperature of the ink; too much packing behind the blanket, and so on. Paper, however, can have the most impact. A vellum sheet will absorb more ink and create more dot gain, whereas a gloss-coated sheet will have little dot gain.
This is VERY important in your design, particularly if you have solids and are running on cover-weight papers since the printer will have to score the sheet. When manufactured, paper creates a grain direction; when paper is sheeted at the mill into parent sizes, manufacturers and distributors indicate grain direction by how they spec out the dimension of the parent sheet, with the second number indicating the grain direction. For example, 25 x 38” means that the grain runs parallel to the long edge (38”). Sometimes you’ll see books where it’s 25 x 38 or 25 x 38. But if you have what is called a “short grain” sheet, the indication is 38 x 25, or 38 x 25 or 38 x 25. Short grain means that the paper grain is running perpendicular to the long edge of the sheet. Grain direction can also affect how the sheet runs through the press, and MOST printers prefer long grain running perpendicular to the sheet direction since the sheet is rolled around various cylinders as it prints.
Most coated sheets are white with variations on whiteness or brightness, blue-white, or cream-white. These variances can affect how the ink will appear, since light passes through the ink, bounces off the paper, and then back through the ink again to your eyes. There are many uncoated sheets that have a variety of colors and finishes, or flecks of recycled material, and this can greatly impact your design. Make sure you get the most recent swatch book from your printer so you can see what that paper will look like. Some print services providers can proof directly onto the paper if they have a high-end proofing system. You may wish to ask that question, particularly if you’re using a paper such as something in the Neenah Environment line.
COVER OR TEXT WEIGHT
Cover paper is, as it sounds, used for covers of books or other publications. Text paper (often called book) is for use in the text of a publication. Now, cover can be coated or uncoated, and text the same. When I started in this industry, text meant uncoated text-weight sheets, and book was for coated text-weight sheets. Currently, you’ll see “coated text” frequently used for coated book.
There are a myriad of sheet sizes dependent upon if the sheet is coated book or text, offset, or coated or uncoated cover. The standards are anything that can come out of either a 25 x 38” sheet, or a 28 x 40” sheet. But even with that, there are variations. For example, 28 x 41” is not uncommon, and 23 x 35” is what you’ll find for text or “writing” sheets. Another common size is 25.5 x 38”. Again, pay attention to grain direction, and ask how your printer plans to run the job, in case he or she is running it in a way that won’t get the best optimization of the sheet.
There is a whole standard for how basis weight is determined, and it can be confusing. Primarily, it’s based on the parent sheet size at a specific amount of sheets. And printers love to use “#” for “pound”, so don’t be too surprised - it’s not a hashtag!
Obviously, thickness of a sheet of paper is crucial and is often directly related to the basis weight. European convention (which is slowly being adopted here in the US) is GSM, or grams per square meter. Digital presses in particular use GSM, and you need to know off the top of your head what your digital device’s max GSM is.
I’ve said it before, and I’ll say it again: paper dummies can truly save your skin, because they are the three dimensional realization of the design you have. Have your print services provider create one for you and one for themselves for reference. Make sure it’s on the actual job stock, and then get the final dieline from the printer to lay your files to.
Designing for print requires more than just a knowledge of layout and composition; it’s also about paper, print, and finishing processes. Understanding all of these factors and how they work together will enable you to design dynamic and cost-effective pieces for your clients.
by John Prothero