Printing Errors to Look Out For

When outsourcing your print marketing materials to a third party printing company, it is natural to expect perfection. However, some printers fail to take the necessary time to check over their print properly, meaning a range of visible errors may occur. Even with reliable print companies, such as Omega High Impact Print Solutions, where we regularly and precisely scrutinize all of our print upon completion, the infrequent mistake is always possible.

For this reason, especially if you’re unsure of the competency of your printing company, it is important to check for faults in grammar, quality of color, and further finishing work in publications, brochures, or even on a sign. This is because, if any element in a given publication appears “off”, it’s very possible for the viewer to question, consciously or unconsciously, the accuracy of your content. The following are some of the most common printing errors to look out for in order to ensure your print is completed to your satisfaction, as well as some possible actions you may be able to take as a customer to prevent them from occurring in the first place.

Scumming

The science behind offset lithography is centralized around the fact that water and oil do not mix together. Because these liquids are immiscible, an offset printing plate can have the image area and non-image area share the same surface. However, this is only true when the amount of water and oil are properly balanced. If the ratio between the two fluids are not properly maintained, ink will print in non-image areas. This means that ink is liable to streak or run, otherwise known as scumming.

While your printer/press tech should be monitoring this balance and performing quality checks throughout the offset printing process, if you happen to be present during a press check, it’s important you watch for scumming, as well.

Doubling and Slurring

When offset printing is done properly, it’s presses roll, causing the plate to transfer imagery to the rubber press blanket, which in turn transfers the image to a given substrate. This, unfortunately, is not always the case. Occasionally, the blanket can make contact with the paper a second time, resulting in the halftone dots appearing to blur. This is called dot doubling. In addition, should the press blanket’s pressure be inaccurate, or the ink tack is insufficient, halftone dots can become elongated. This is commonly referred to as slurring.

Should you be present during the printing process, these flaws are not always directly visible. However, they are usually spottable on the printer’s control targets for dot gain, slurring, and doubling. So if you are able to, or are so inclined, try to pay attention to this tool in order to make sure this is not an issue.

Set-off

After a print technician has finished printing a stack of press sheets, and they wish to flip the stack over in order to print on the opposite side, it’s imperative that they allow time for the ink to dry first. Otherwise, the ink will set off from one press sheet to the back of the subsequent press sheets while printing the back. Even if the sheet isn’t backed up prior to the ink drying, the image can still be offset as a result of the weight of the press sheets on one another.

In all reality, processing press sheets in any way, including trimming and folding, while the ink is still wet can cause set-off. Therefore, the most important thing you can do as a customer is not to rush your order, and to be realistic about the time it may take for your job to be completed. Bear in mind that some colors of ink take longer to dry than others, and that areas of print that require heavily layered ink also have a longer drying time than areas with light ink coverage.

Hickies

When printing plates and blankets are not adequately or regularly cleaned, dust and paper particles can become stuck to them, and obstruct proper ink application. This often results in the appearance of tiny white ringlets with solid ink centers on printed press sheets.

While this effect can be minimized by maintaining the cleanliness of the press, unlike the aforementioned printing errors, it cannot be entirely eliminated. Over the course of any press run, these rings will appear on at least a few press sheets, but should disappear soon thereafter. These are called hickies, and they are the result of small bits of ink, paper, coating, press dirt, and dust becoming trapped within the press itself. This is ultimately inevitable no matter how well or often the machinery is cleaned, although print companies that maintain superior cleanliness standards, such as Omega High Impact Print Solutions, will be able to keep hickies down to an absolute minimum.

While printing errors are bound to happen from time to time, it is important to understand what these potential mistakes are, what causes them, and how or if they can be prevented. Knowing the ins and outs of what your printer is (or should be) seeking to avoid can help you make smarter decisions in choosing what company to outsource your print to, as this can give you greater insight into a printer’s level of experience, expertise, care and attentiveness.

If you are able, it can be very helpful to attend a press inspection now and then, in order to really get a firm grasp on these potential flaws, and to determine the competency of who is manufacturing your print. After all, if your printer is confident in their ability to bring you quality print (nudge-nudge, wink-wink) they will be more than willing to allow you to be an active part of the printing of your materials!

Written by Omega High Impact Print Solutions' Digital Marketing Specialist, Emily Steel