Successful Color: Consider the Basics
By Steven Strooh
Inconsistent or inaccurate color remains one of the most common reasons for work being rejected by customers.
Wide-format printing is a rapidly growing industry, with applications ranging from signage and banners to vehicle wraps and point-of-purchase displays. As the demand for wide-format prints increases, so does the need for color consistency. Inconsistent or inaccurate color can be fatal to a hard-won reputation and your client relationships, especially with the short cycle times print producers face these days.
Color consistency is critical in wide-format printing because it ensures that the colors of a print are ‘visually similar’ to the colors of the original design. This is important for both aesthetic and practical reasons. From an aesthetic standpoint, color consistency helps to create a cohesive and professional look for a wide-format print project. From a practical perspective, color consistency ensures that the colors of a print are accurate over time, especially if not all the graphics are being replaced simultaneously. Even slight inconsistencies at this stage will be glaringly obvious. Wouldn’t it be nice not to have to explain why there were differences between the prints you made last year and these new ones? Sometimes there are environmental changes for which you cannot be held responsible.
There are several challenges to achieving color consistency in wide-format printing. One challenge is that different ‘white’ media colors can vary significantly. On different plastic substrates, for example, the colors of a print on a Sintra® media will differ from those of the same print on Styrene, which has a distinctly blue tinge. Another challenge is that the colors on different devices can also vary. For example, the colors of a print on a customer’s color inkjet printer will be different from the colors of the same print on an industrial wide-format printer. Besides the lack of calibration on the customer’s printer, it will print directly as an RGB device. On the other hand, a wide-format printer at your facility will print via a RIP as a, broadly speaking, CYMK device.
To achieve color consistency in any printing process, it is essential to use various tools and techniques. A wide-format printing facility is no different. It is necessary to have a non-sheetfed spectrophotometer, with which you can measure the colors on various medias and devices and then adjust your printing process to ensure that the colors of your prints are accurate. Most facilities typically have a hand-held X-Rite i1Pro 3 or i1Pro 4 device. This allows manual measuring of reference swatches for color profiling, usually through the RIP software. Manual measurements are perfectly adequate if somewhat slow. In some facilities, investing in an XY table may be more efficient, which will allow measuring to be more precise and quicker.
Another critical tool for achieving color consistency is lighting. The lighting in your printing facility and, preferably, your whole environment can significantly impact the appearance of your prints' colors. To ensure that your prints are accurate, from prepress and production to where a client or CSR may be viewing them, it is crucial to have a consistent lighting source. These days overhead LED lighting can be acquired in the recommended 5000K specification. If you are unsure what the color temperature of your lighting is, use your phone’s camera as a Color Meter with the free Pocket Light Meter iPhone app.
Finally, it is essential to use a standard color management workflow. A color management workflow is a set of procedures to ensure that your prints' colors are accurate. Typical steps include regularly calibrating your devices and creating custom profiles for each media and printer using a RIP or color management software such as X-Rite’s i1Publish.
You can achieve color accuracy and consistency in wide-format printing using the right tools and techniques. This will help you create high-quality prints that meet your customers’ expectations. Attracting and impressing brand-forward clients almost always requires a color management process that includes robust quality control. They often request documentation of your process and your facility's color certifications, such as the Idealliance G7 Certification.
Here are some additional tips for achieving color success in wide-format printing:
- Use a consistent ink and media combination. Limit how much you switch media types and vendors to ensure that your prints are accurate and consistent throughout your facility. Given cost inflation and supply chain issues, I understand that this is sometimes unavoidable. However, it can be a false economy saving a few cents per square foot if your reputation for color quality is compromised. It is also possible that the same vendor can switch its manufacturing process or materials. Suppose the media changes, or you see unexpected differences in the color output. In that case, it is essential to reprofile the new media to maintain accuracy and consistency with previous work for your clients and color output across your facility.
- Calibrate your devices regularly. Sometimes you may hear the word linearization bandied about, which can mean the same thing but is often shorthand for "making the device better behaved!" Calibration software aligns input with output color values by printing a small series of reference colors, and the output is measured and corrected where necessary. Your devices can drift out of calibration over time. Ensuring that your custom profiles produce accurate and consistent color requires regular device calibration. This means bringing the device into the same printing conditions during which the custom profiles were created. The software will adjust the device so that the right amount of ink is laid down for each device’s color channel from the lightest to the darkest.
- Use color management software or the built-in media management system in most RIPs. The software will help you control your prints' colors by creating custom profiles for each media on each device. This will improve the chances that colors will be visually similar throughout your facility.
- Print test samples. Printing test samples before you print a final job is always a good idea. This will help you ensure that your prints' colors are accurate.
Get feedback from your customers. Ask your customers for feedback on the colors of your prints. If a particular color appears different to your client than they were expecting, you may have to adjust for that specific client. Ultimately, the goal of successful color is to reliably meet your customer's expectations.