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Paper 101
- 1. Paper Properties andTheir Impact on the Printing Process
- 2. 2 Why is KnowingPaper Important to you?Why is Knowing Paper Important to you? 1) Paper and other substrates on which an image is printed can represent 25-55% of the final cost of a printed job 2) Having a working knowledge assures that the paper selected is the most appropriate and cost effective for the application
- 3. 3 Basics of PaperManufacturingBasics of Paper Manufacturing 1. Forests 2. Logging – debarking 3. Pulp refining 4. Forming Section (wet end), Press Section (water removed), Drying Section (sets moisture levels) 5. Calendaring (final stages for smoothness, etc) 6. Cutting down the 40,000 lb plus rolls ready for finishing (rolls or sheets) 6.
- 4. 4 Paper Making Kit Plus,a Question
- 5. 5 Paper Machines arethe length of football fields!!!Paper Machines are the length of football fields!!!
- 6. 6 Key Properties ofPaperKey Properties of Paper Fibers Basis Weight Caliper (Thickness) Grain Direction Formation Surface Sizing Opacity Brightness Whiteness Absorption Smoothness Paper Strength Stretch Moisture
- 7. 7 Wood Fibers Usedin Paper ManufacturingWood Fibers Used in Paper Manufacturing The fibers used in paper manufacturing play a key part in what happens to it later •Hard woods •Southern climates •Shorter fibers •Weaker, yet smoother •Coniferous trees •Northern climates •Longer Fibers •Stronger, yet rough •Eucalyptus trees •Southern hemisphere
- 8. 8 Fibers Used inPaper ManufacturingFibers Used in Paper Manufacturing Paper can be made from MANY sources, but wood fibers are used more often Other paper fibers sources can include: • Cotton and other plants (i.e. hemp) • Recycled fibers • Hemp • Rice • Even old jeans!
- 9. 9 Basis Weight ofPaper ---- Huh?Basis Weight of Paper ---- Huh? Basis Weight is paper weight in pounds of a ream (500 sheets) in it’s basic size Web Printers purchase paper by weight (pounds) in rolls. Sheet fed printers typically order by number of sheets needed for the job. Example: The basic size for Book papers is 25” x 38”. The measurement of basis weight for book paper would be calculated by taking 500 sheets each measuring 25” x 38” and placing it on a scale. If the weight of the 500 sheets was 50lb., we would call that paper 50 lb. Book. If the weight was 60 lb. it would be 60 lb. book.
- 10. 10 Basis Weight Types– Basic SizesBasis Weight Types – Basic Sizes 1) Cover (20” x 26”) a. Heavy weight papers used for book covers, advertising, direct mail, etc. 2) Index (22 ½” x 28 ½” and 25 ½“ x 30 ½ “) a. Usually available in smooth and vellum finishes. Used in file folders, index cards, etc. 3) Tag (24” x 36”) a. Smoother surface than index, making it ideal for high-speed folding, embossing, etc. 3) Bond (17” x 22”) a. Commonly used for letters and business forms. Example: paper in your books is 20# Bond
- 11. 11 Basis Weight Types– Basic SizesBasis Weight Types – Basic Sizes 5) Board (22 ½” x 28 ½”) a. One of the board grades, with a softer surface than index or tag. Used for POP, signage, book covers (soft), advertising etc. 6) (25” x 38”) a. Coated Book b. Uncoated Book c. Text d. Offset Much easier outside the U.S.… They use only one Basis Weight.
- 12. 12 Let’s look atsome Swatch Books
- 13. 13 Basis Weight ascompared to CaliperBasis Weight as compared to Caliper Basis weight is the weight in lbs of a ream of paper in its’ basic size Caliper is the thickness of the paper
- 14. 16 FormationFormation Formation is thephysical distribution and orientation of fibers and other solid constituents in the structure of a sheet of paper which affects the appearance and other physical properties. Formation is also referred to as “look through” because the formation can sometimes be observed by looking through the sheet.
- 15. 17 FormationFormation Formation can havea big impact on print quality for: a. Ink Mottle - A “wild” formed sheet will result in the ink absorbing into the structure unevenly which then causes the ink to day with a mottled appearance. b. Ink Show-Through (Printed Opacity) - If a sheet is “wild” with areas of fiber surrounded by areas of no or little fiber, ink will bleed at differing rates resulting in a strong “blotchy” ink show-through.
- 16. 18 Surface SizingSurface Sizing Surfaceis a key to good press runnability! a. Uncoated papers need to “seal” the sheet to reduce press contamination (fiber, debris, etc.). b. Sizing used for uncoated paper consists of a starch applied to the paper during the paper making process. c. Various types of starches are used: Corn Potato Ethylated Cationic Starch Oxidized Etc. Good surface sizing is critical to achieve good press performance!
- 17. 19 Surface SizingSurface Sizing Starchis applied by a simple “coating device” located between the two drying sections of the paper machine. There are several types used by paper makers to applied starch. A typical size press would look like this: Paper Size Press Rolls Starch Solution
- 18. 20 Optical PropertiesOptical Properties 1)There are five main optical properties that influence the visual perspective of a printed sheet: a. Opacity b. Brightness c. Whiteness d. Color e. Gloss
- 19. 21 OpacityOpacity Opacity relates tothe show-through of the printed image from the opposite side of the sheet, or the sheet under it.
- 20. 22 BrightnessBrightness Brightness affects thecontrast, brilliance, snap or sparkle of the printed sheet. It is the percent of reflectance at a standard single wavelength. a. Don’t confuse “whiteness” with “brightness”. b. Whiteness is the amount of Red, Blue and Green reflectance and that will be discussed shortly
- 21. 24 73-78.973-78.9 79-82.979-82.9 83-84.983-84.9 85-87.985-87.9 88+88+ AF&PA Brightness ComparisonAF&PABrightness Comparison 81.9 and below81.9 and below 82-86.982-86.9 87-90.987-90.9 91 +91 +NO.1NO.1 NO.2NO.2 NO.3NO.3 NO.4NO.4 GE BRIGHTNESSGE BRIGHTNESS METERMETER PremiumPremium Old New
- 22. 25 WhitenessWhiteness 1) Whiteness isthe ratio of Red, Green and Blue reflectance. a. An attribute of a diffusing surface which denotes its similarity in color to preferred or standard white. A psychological attribute of a color stimulus. A “white” color stimulus is perceived as void or any hue or grayness. a. White can be in many different hues. Known as “cold” if on the blue side. Known as “warm” if on the red side.
- 23. 26 GlossGloss 1) Gloss isthe relative amount of incident light reflected from a surface. a. Paper Gloss - Degree to which a paper surface appears “shiny”. b. Printed Gloss - Degree to which a printed ink appears “shiny”. 2) Paper Gloss is attained by the paper maker through calendering and pigments. a. The higher the calendaring, the higher the gloss.
- 24. 27 CalenderingCalendering Paper Calendar Rolls Pressure andheat combine to make the sheet shinier and glossier. However, the more you calendar, the thinner the sheet becomes.
- 25. 28 Coated Paper FinishExamplesCoated Paper Finish Examples Finish Calendering Paper Gloss Surface Suggested Matte None Not apparent Rough/toothy, non-glare Texture, Text Dull Minimal Very Low Smooth, non- glare Illustrations, Black & White Satin/Velvet Light Low - Moderate Smooth and soft to the touch Text, texture, fabrics Silk Light Moderate Smooth and silky to the touch Fine art, skin tones, detail, readability Gloss High High Smooth, shiny, slick Hard, shiny surfaces, no scuff
- 26. 29 Gloss Finished SurfaceGlossFinished Surface Calendared using smooth and polished steel rolls Smoothest surface Highest printed ink gloss Highest plain paper gloss of coated finishes -- reflective Highest ink hold-out, lowest dot gain Best for showing fine detail
- 27. 30 Matte Finished SurfaceMatteFinished Surface Non-glare surface Textured, Roughest Minimally calendered a. Lowest paper gloss b. Lowest printed ink gloss c. Greatest amount of contrast between paper and ink Replicates look and feel of uncoated End Uses: Text, charts, anywhere to minimize eyestrain, writeable
- 28. 31 Silk / DullFinished SurfaceSilk / Dull Finished Surface Non-glare surface Micro-embossed surface, pattern from imparted by calendar rollers Excellent ink holdout for sharp halftone reproduction Softer images Richer halftones and solids than mattes
- 29. 32 Velvet Finished SurfaceVelvetFinished Surface Coating formula and on line calendaring technique produce a smooth, low gloss paper Looks like a dull -- prints like a gloss Higher paper gloss than a dull Similar coat weight to gloss Smoother, harder surface than a dull More uniform printing surface than a matte Distinctive, silky feel A.K.A. Satin, Suede
- 30. Global Coated Papers:Worlds of DifferenceGlobal Coated Papers: Worlds of Difference North American AsianEuropean
- 31. 34 Uncoated versus CoatedPapersUncoated versus Coated Papers
- 32.
- 33. 36 Un-Coated Print DotUn-CoatedPrint Dot Coated Print DotCoated Print Dot
- 34. 37 SmoothnessSmoothness Measures texture andtopography Necessary for continuous, non- mottled ink film Higher ink gloss More pure ink color/broader tonal range More accurate reproduction Greater detail for critical color Products Corporate Identity
- 35. 38 StrengthStrength 1) Strength ofpaper is more dependent on the nature of its fiber than its thickness. a. High bursting strength is achieved by closely intermingling long pulp fibers during the forming of the sheet on the paper machine. b. Fibers are long and tear in the cross machine direction is always higher than tear in the machine direction. This is because the greatest number of fibers lie across the path of the cross machine. a. Tear strength is important when producing a sheet with perforations. The “perf” should not fall apart of be difficult to separate.
- 36. 40 StretchStretch Stretch is theamount of distortion paper undergoes under tensile strain. Stretch is generally much greater in the cross direction than in the machine direction. a. Excessive stretch with web or sheetfed papers will result in poor registration or fanning problems.
- 37. 41 MoistureMoisture The Moisture contentis the percent of moisture found in the finished paper. a. Can range from a low of 4.0% to a high of 7.0%. b. Heat-set web paper with low moisture (< 5.0%) will dry out in the heatset oven causing cracking at the fold. 1 ton of paper at 5% moisture level will contain 100 lbs. of water! Remember earlier when we talked about the paper machine? Paper is 95 to 98% water as it enters the paper machine! Moisture in paper plays a part from the beginning all the way through the printing process.
- 38. 42 MoistureMoisture Paper likes tocome to equilibrium with its environment. a. Paper brought into a humid pressroom absorbs moisture at the edges while the rest of the pile or roll (towards the center) will remain unchanged. b. As this process occurs, the edges containing more moisture will increase in size resulting in wavy edges. c. Paper brought into a dry pressroom will give up moisture, at the edges first, shrinking the paper resulting in tight edges. This will result in wrinkles, fanning and bad registration.
- 39. 43 Specialty Grades ofPaperSpecialty Grades of Paper Fancy finishes Synthetic Papers Magnetic Papers Pressure Sensitive (i.e. “sticky back”) Carbonless Etc
- 40. 44 Educational ResourcesEducational Resources 1)Spicers Paper a. Environmental calculator b. other tools 2) International Paper Pocket Pal a. www.ippocketpal.com 3) The “Coated U” from Appleton 4) Sappi Standards 5) Paper mill swatch books 6) Many more!
- 41. 45 OFFICES Corporate Office 800-774-2377or 562-698-1199 Los Angeles 800-774-2377 or 562-698-1199 Las Vegas 702-736-4441 Phoenix 800-352-5749 San Francisco 866-774-2377 Denver 303-373-9655 Portland 800-452-8401 or 503-405-0100 Seattle 253-518-0015 or 800-231-5136 Honolulu 808-832-0001 Minneapolis 877-634-0024 Kansas City 888-333-0055 St. Louis 314-801-6100 Salt Lake City 801-364-0113 or 866-403-6609
Editor's Notes
- #16 Have each person tear a sheet of paper. “trick” them by doing a grain short sheet.
- #25 &lt;number&gt;
- #28 &lt;number&gt; When paper emerges from the last dryer, some grades are ready to be rewound, wrapped, and shipped. But some paper from the machine goes though an additional finishing step off line. Some papers, like mattes and silks, are finished in line on the PM and are calendered. Most of our gloss and dull papers go off line to a supercalender. A supercalender is a series of resilient rolls set one on top of the other. Alternately metal/steel and soft/cotton resilient rolls. Paper enters the stack at the top and the fibers are polished and compressed; it is compacted and smoothed progressively as it travels down the stack. As the paper moves between the rolls, they exert varying degrees of pressure on the paper. The hard metal rolls press into the resilient rolls at the nip, producing a polishing action that imparts varying degrees of smoothness and gloss to the paper. This process, combined with heat, is known as calendering. The degree of smoothness and gloss is determined by the amount of pressure, surface of the rolls, and number of nips, or passes through the calender. In some processes, as in our dull process, we use embossing, which gives the paper a pattern finish. The metal roll carries the embossed pattern. When the paper passes between the embossed roll and the cotton roll, the pattern is imparted onto the paper. Coating chemistry dictates calendering outcome. Heat not a factor with this process. Not enough heat generated by friction to impact.
- #30 &lt;number&gt; It is commonly used to show high amounts of detail. Bright colors.
- #31 &lt;number&gt; End up with a lower sheen than gloss or dull paper. Appropriate for a wide variety of printed materials; common in books. Printed ink gloss on matte papers is better than on uncoated paper. Still low because ink pigments don’t lie evenly, and some of the resins sink into the sheet.
- #32 &lt;number&gt; (As noted.) In our mills, we use a microscopic design to impart a uniform pattern on the sheets. This pattern results in a low gloss surface.
- #33 &lt;number&gt; As above.
- #34 &lt;number&gt; Note that imported coated papers in NA are manufactured to NA standards. Note differences in thickness of coating and fiber from different markets NA - most fiber least (highest quality) coating E - least fiber/most coating A - mid range for fiber and coating
- #36 &lt;number&gt; Premium Uncoated A smooth text and cover sheet finish that softens the image and enhances the tactile quality of the surface, adding dimension to touchable materials.
- #37 &lt;number&gt;
- #38 &lt;number&gt; What this means to you! Smoothness enhances reproduction because it reflects light back to the viewer in straighter lines (specular) , which keeps the images sharp and clear. Rougher surface: Solids may look uneven Scatters light, diffusing detail, graying colors, sometimes changing their hue. Critical Color: Products, Corporate Colors Pleasing Color: Everything else. Food, Flowers, People, etc.