Heavy Coverage: Ten Job Saving Tips

When printing with solid colours, you often may want to achieve the dramatic effect that accompanies a large section of heavy coverage. For a number of technical reasons, however, we need to work even more closely together to ensure that your vision for the piece is consistent with what is delivered. With this issue, we have outlined a variety of steps to avoid a large let-down when designing with large areas of solid ink.

Ghosts of Printed Last?

Printing terms relevant to a discussion of heavy ink coverage

Uneven/Inadequate Density

Optical density is the intensity of the colour or printed image. While often referenced to black and/or white, the density of a solid colour can be measured as well. The more dense the colour, the richer it will appear.

Mechanical Ghosting

Ghosting is a faint, unintended shadow or form appearing in the final piece. Mechanical ghosting is typically a result of press conditions or form layout with excessive overall ink coverage.

Chemical Ghosting

Chemical ghosting is most often the result of a slight offset transfer or vapor transfer of an image, usually weak, from one just-printed sheet to the back of another. Its appearance may occur gradually as the printed piece fully dries.

Mottling

Mottling is the spotty, uneven or non-uniform appearance of solid ink. It most likely will appear in areas of heavy ink coverage.

Our Not-So-Motley Crew

Our team has a number of options to minimize potential heavy-coverage issues

Double Hit It

With a double hit, we will print your solid colour with one of the plates of our press, and then a second time with a second plate on a different unit as the sheet passes through the press.

Bury a Build

We can print the closest four-colour process match of your solid first, and then print the solid colour on top of it. This requires five total plates.

Hint of Tint

Alternatively, we can print the area of heavy coverage with a 20-40% tint of your solid colour, and then lay down the 100% solid on top of the tint with a second plate.

Varnish Tint

A novel approach to boosting the colour density is to first print the solid ink either alone or in combination with of the techniques above, and then to add a varnish tinted with the same hue as the underlying colour.

White Wash

We can print an opaque white behind the solid-colour ink, sealing the sheet similar to how paint seals wood. We print the colour right on top of the white ink. Note that the white must dry before the colour can be printed, requiring two passes through the press.

Varnish Rather than UV

A tinted varnish as we discussed above may be a preferable solution rather than UV coating, since UV coating can crack wherever it is folded. If your solid ink coverage crosses a fold and the UV causes the paper to crack, you might see the white of the paper showing through along the edge of the crack.

Super-Sized Sheet

With a larger sheet, there is less overall coverage as a percentage of the surface area of paper. It also allows us to add a "take-off bar," a special set of printer's marks that even out the lay-down of ink, helping to avoid ink "starvation" in one specific area of the sheet. This solution gives us added flexibility at the cost of slightly higher paper costs and waste.

Built with Tilt

Cracking can sometimes be minimized by running the job at a slight tilt or angle as it passes though the press. This greatly complicates scoring, trimming and folding, however, and is not a typical solution we would advocate.

Imposition Fruition

Imposition is the placement of the pages on the form, or press sheet. Often, the most cost-effective (and quality-effective) solutions may involve the creative imposition of your job. Once again, the earlier you talk to us and the more information we have regarding coverage on each of the pages of your project, the better we can design a form that gets the best colour at the lowest cost.

Talk Is Cheap(er)

The best way to avoid these problems is first and foremost to review your project with us and your concerns as early in the process as possible. Together, we can evaluate the benefits and associated costs of a variety of techniques to limit adverse outcomes on even the most complex of jobs. So give us a call... we are here when you need us.