Hi, I'm Burt.

Not to brag, but words like “brilliant”and “vivid” are often associated with my work. But enough about me. Let’s talk about you and your project.

Note my “notes” on everything from paper selection and environmental impact to on-press proofing. I’m here to assist you with any questions you may have.

Get creative and don’t be afraid to ask questions or explore new options!

Whether you are a designer or a printer, it’s always inspirational to see great results and work within the industry. Enjoy.

And if you have any questions about uncoated paper, shoot me an email at burt@Domtar.com or contact your Account Manager.

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Burt's basics, step-by-step.

 

Why choose uncoated paper?

It's good for your image.

There was a time when uncoated papers were considered inferior to coated. However, technology and trends have greatly changed. There have been tremendous advancements in papermaking and printing. We have also become much more creative in our use of coatings and varnishes. Sharp, full color reproduction combined with the smooth surface finish, brightness, opacity and substantial overall feel is making uncoated paper an increasingly popular choice among a new generation of savvy designers. And the results are brilliant.

With Domtar Cougar®, Lynx® Opaque Ultra, and Husky® Opaque Offset product lines, you’ll find the ideal paper for a piece that
will unquestionably project an exceptional image.

It's environmentally responsible.

Domtar is North America’s largest integrated manufacturer and marketer of fine paper and a leader in sustainable practices.
With Domtar EarthChoice¨, we are proud to offer the largest family of environmentally and socially responsible papers ever assembled. Manufactured to Domtar’s high standards, this line is Forest Stewardship Council (FSC®) certified and Rainforest Alliance Certified. No wonder it’s burt’s premier choice.

Paper selection

Paper is an important design element and should be considered early in the process. To get the best results when printing on uncoated paper, make sure you choose the right sheet for the job. That means carefully thinking through all the functions your paper must perform.

  • Consider both the personality and lifespan of the piece. Is it going to be mailed? Or perhaps it’s a brochure or catalog that will be handled repeatedly. It’s important to think through durability, cost per piece, and post-press techniques you wish to apply.

  • If you are designing a self-mailer, be sure to discuss postal guidelines with your printer to avoid incurring additional U.S. Postal Service fees.

  • Determine the weight of the paper based on the end use. Pay particular attention to such factors as finish, color, brightness, opacity, ink holdout, stiffness and bulk.

  • Pick a smooth sheet when print quality is a key factor and vellum when a tactile feel is a priority.

  • Look at a swatchbook for brightness; be aware that the whiteness of a shade will affect the appearance of the ink. Because inks are transparent, the color/shade of the base sheet will impact the overall hue of the image.

  • Find out where your paper comes from, and require third-party certification such as FSC¨, SFI¨ or PEFCª. This ensures that the fiber used to make your paper was managed and harvested responsibly.

  • Once you have specs, have a paper dummy created to be sure you’ve selected the right weight and finish. Get samples showing the specific techniques you will be using in your project. The paper dummy can also be used to optimize the job with respect to ink coverage and scoring layouts.

Evaluating artwork

Reproduction criteria for uncoated paper are essentially the same as for any other paper; however, the right artwork can make all the difference. Maximize the use of uncoated by choosing photography and artwork with a full range of tones. While midtones and shadows are usually the most challenging to reproduce, there are some relatively simple adjustments and ways to color-correct images before going to press.

b.notes

  • Remember, just because it looks good on the computer screen doesn’t mean it will translate well on paper. Involve your printer early on.
  • Try to select images that are open, and not heavily saturated.
  • Avoid enlargements that lack sufficient resolution for printing. Avoid blurry images/techniques that can inadvertently translate to a mottle in print.
  • Be careful with large screen builds. Try to select colors that are more forgiving on press, like orange, gold and black.
  • Try to select or specify images with good midtones and shadow detail.

Making separations

Separations must be tailor-made for every paper coated and uncoated. Because of absorption and, to some degree, paper texture, halftone dots tend to spread, deform and connect (a.k.a. “dot gain”). As a result, well-planned separations are probably the most important part of the production process.

Dots & screens

Dot Control

Dot gain occurs on uncoated paper more than on coated papers due to ink absorption into the sheet. By adjusting for dot gain during the color separation process you can increase contrast, improve highlights, and reduce muddying of shadow areas.

b.notes

  • Allow for approximately 16 percent more dot gain on an uncoated sheet versus a coated sheet.
  • While formulas for making adjustments vary from printer to printer, as a rule highlight dots are reduced by 5 percent, midtone dots by 25 percent and shadow dots about 15 percent.
  • Adjust press curves to reduce dot size at both ends of the screen curve to prevent plugging in shadows.

Dot Shape

Choice of dot shape (square, round or elliptical) is determined by both press requirements and aesthetics. Most printers will have a preference and can discuss their methodology from the outset of the project.

b.notes

  • Square dots, which are the most common, are thought to give the best definition of fine detail, but may cause midtone “chop” or roughness in large smooth areas such as skies.
  • Because 50 percent elliptical dots connect only at their ends, they also mitigate the effects of dot gain, yielding smoother gradation among adjacent tonal areas and reducing “tonal breaks” or rough textures in, for example, skin tones.
  • Round dots may be the best choice when heavy dot gain is predictable, such as on newsprint or on high-speed web jobs. They do not connect until they reach about 70 percent of maximum size; thus they extend midtone range and minimize loss of midtone and highlight quality.

Screen Ruling

Screen ruling determines dot size and frequency. The finer the screen, the smaller and more numerous the dots. Be aware that there is a common misconception that small dots lead to better reproduction. Because there is a direct relationship between screen ruling and dot gain, a finer screen does not automatically produce a better image.

b.notes

  • The more open the paper surface, the greater benefit achieved from a lower line screen.
  • In general, run halftones with a screen of 150 lines or less and stay away from tints of 5 percent or finer (although under controlled conditions you can reproduce screens of up to 200 lines per inch and achieve even finer tints on smooth uncoated stocks). Premium papers can easily allow for 175 - 200 line screens.
    For best reproduction, do not specify a line screen finer than needed and do select a paper with a smooth, uniform surface.

Stochastic Screening

This technology uses the same size dots, but, rather than structuring them in a uniform grid of columns and rows, stochastic screening creates tones by varying the number of dots in an area.

  • The screening of four colors is no longer made with four different angles as with the traditional screen, therefore it eliminates screening moire.
  • Stochastic screens can print as many colors as needed to match virtually any color.
  • Because of the small size of their dot  (the largest is tinier than 0.10 percent dot in a conventional 150 line screen) stochastic screens produce sharper images.

Paper handling

It is important for the press to be in a controlled environment with a stable temperature and humidity. Optimal conditions are a temperature of 68º-76º F (20º-24º C) and a humidity of 35-55 percent. Paper should always be acclimated to the pressroom by allowing it to reach the room’s temperature before removing protective wrapping.

b.notes

  • Paper received from a truck or a warehouse should be allowed to reach room temperature before it is unwrapped.
  • Bring the paper into the pressroom 24 hours before opening cartons or removing ream wrappers. This is especially important during cold weather. Do not unwrap the paper or remove it from cartons during this process.
  • Don’t store paper in direct sunlight or in doorways.
  • Don’t stack cartons on end, keep the paper flat.
  • Don’t stock cartons on cement floors, use pallets.
  • Keep the floors clean and free of dust and grit.
  • Don’t destroy labels. Keep the paper identified.
  • Reseal opened cartons. Rewrap opened skids.

    Pre-press

    Pre-press is a multistage process that starts by converting the files to develop a plate/proof curve that compensates for the greater dot gain inherent in uncoated paper. Printers apply curves to the proofs to manage color and, equally, expectations. It cannot be overstated that the experience and intuitive eye of a true craftsman (both pre-press and on-press) will make all the difference in reproduction.

    Preparing Files: Plates are built via a series of dots to reproduce solids, shades, light and dark. The printer can manipulate and correct image resolution/sharpness by adjusting dot size, shape and density.

    Pre-press Proofing: Proofs are produced from digital data that can be used to simulate plate, ink and paper effects. After the proof is run, images should have the hue and intensity you are looking to achieve. Check shadows, highlights, shaded areas, halftones and flesh tones. Note that color won’t appear exact as proofs are typically generated on a special proofing paper that is most commonly coated.

    b.notes

    • When printing large solid black areas, consider building with CMYK or double bumping “K.”
    • When printing a gray, do not build from CMYK if at all possible, as this significantly limits options with control.
    • Each press is going to print differently, so you may need to run a target sheet (“fingerprint”) for a baseline to calibrate your proofing devices.
    • Color adjustments can be made to individual areas of the image during the prepress proofing stage.
    • Be aware that most proofs are inkjet based. Resolution/sharpness may be different on uncoated paper unless dot gain curves are  properly applied.
    • You may apply an uncoated color curve to digital color proofs in order to match the proof with the press.
    • Proof a blueline from the printer to make sure layouts are correct.
    • Making as many adjustments as possible in the proofing stage will save you time and money on press.

    On-press proofing

    A good press proof closely duplicates the condition of the eventual run, employing the same imposition, plates, ink and press type. Most important, it is made on the paper chosen for the job rather than on a special proofing paper, which may imitate coated paper.

    b.notes

    • Use inks designed for uncoated paper. Work with the ink supplier to optimize ink tack. Keep ink tack below 14 to minimize opportunity for picking.
    • Low ink tacks are more likely to result in increased dot gain.
    • Run hard drying inks as opposed to a stay open ink.
    • The press blankets should be quick release.
    • Once the first press sheet is approved, it should be used for color comparisons for the duration of the run.
    • Always check proofs both wet and dry since colors will change slightly as the ink sets, a phenomenon known as “dryback.”
    • Review match and process colors. Check solids for look, density and consistency.
    • For truer colors, explore the benefits of using an extra PMS if the press has the capability.

    Press adjustments

    On-press adjustment capability will vary from printer to printer depending on strategic technological investments made by each individual shop.

    Press adjustments may need to be made specifically for uncoated paper. Sheetfed press adjustments can be made for each side of the sheet individually, while web press adjustments (such as impression cylinder pressure) impact the image on both sides simultaneously.

    b.notes

    • Uncoated paper generally requires blanket wash ups every three rolls or after each skid (sheetfed).
    • Consider the amount of squeeze/impression cylinder pressure, ink sequence and press chemistry.
    • Maintain a fountain solution target pH range of 4.5 to 5.5 to minimize filler leaching or ink drying issues.
    • To keep screens smooth, try over-packing your blankets or put a new set of blankets on the press.

    Post-press techniques

    Your piece has been skillfully printed. The colors are vivid and your images look great. However, it’s not until the finishing stage that your project takes its final form and comes to life. From the outset of a project, don’t assume special techniques are out of reach. There are many ways to make your piece more functional or give it an attention-getting twist.

    b.notes

    • Talk to your printer about in-house finishing options, including: trimming, embossing, foiling, die-cutting, scoring, folding, binding (adhesive or saddle stitching) and handwork.
    • Popular folding styles include letter fold, accordion fold, gate fold, roll fold, parallel fold and broadside.
    • Unique folds may require specific grain orientation to maximize the folding efficiency. Consult your printer prior to placing the order to ensure the proper stock selection.
    • When embossing, check for un-sharp edges, pinholes, ruptures and “halos” (shadows around the emboss).
    • When foil stamping, check for feathering, color changes, scuffing, peeling and un-sharp edges.
    • Make sure die-cuts are cleanly cut and in the correct position.
    • Before printed sheets are folded or bound make a trimmed dummy to check for correct alignment and pagination.

    Burt’s words of wisdom

    Get creative and don’t be afraid to ask questions or explore new options.

    If you don’t already have swatchbooks for Cougar, Lynx, and Husky, you can always conveniently order at Domtar.com, where we also regularly post exciting project samples.

    Whether you are a designer or a printer, it’s always inspirational to see great results and work within the industry. Enjoy.

    And if you have any questions about uncoated paper, shoot me an email at burt@Domtar.com or contact your Account Manager.

     

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