Why Did My Blue Print Purple?! How to Avoid the Color Shift

Blue Printed as Purple

“My perfect new reflex blue brand color printed PURPLE!”

Whether you are a designer or business owner who hired a designer,  you expect your color choices to look the same on paper as they did on your desktop monitor — and also the same on your boss’ cellphone where he viewed your proof, on your website where a coworker converted your design into a webpage, on signage, on packaging, and on all your marketing tools that will reach your audience. What sounds deceptively simple at first is actually a VERY tall order in a world where color reproduction and color perception are influenced by so many factors. 

That’s where the collaboration between a  trustworthy printer and experienced designer come to the rescue! Technology makes the creation, production, and sharing of amazing designs incredibly easy. And while color management is now standardized and more affordable than in comparison to “the old days,” it is NOT a given and requires more understanding and communication up front to avoid any pitfalls and nasty surprises at print time.  Digital speed has still not changed some basic, unalterable facts of the science of color and how our eyes perceive it. Your blue came out purple because of the divide between RGB and CMYK color gamuts.

Color spectrum - RGB & CMYK gamuts
Color Gamut Comparison

In simplest terms, the colors available in the RGB color gamut (what you can see on your screen) are much greater than the colors available in the CMYK gamut (what can be printed). There are many ways print professionals try to minimize the color shift in the conversion from RGB to CMYK, but they are not all perfect solutions and some colors reveal much more visible differences than others. While the RGB gamut can display a large number of shades and nuances in darker blues, the CMYK gamut is more limited. In trying to reproduce those faint differences, the cyan and magenta used to create the blue with ultimately blend toward purple. Understanding this way back at the point of inspiration and design is essential to avoiding disappointment at the point of print.

One of the most standard ways to guard against unwanted results (like purplish blues) is to base designs in the Pantone® Matching System library of colors. If you define the blue in your design as a specific PMS blue, then your printer will know, and then be able to take steps to match the color against this “universal” standard. You will both have a standard against which to measure your blue. It is like a built-in instruction of how the color should be rendered.

Reflex Blue Swatch v. ProcessDefining a “spot blue” in your work does not mean you must always print offset, using the spot ink. Still, it gives your printer a marker of what you intend that blue to be at output. Now here comes the next hurdle – you will need to take into account the color shift that will happen when printing a PMS-defined color in CMYK. Again, we can thank the differences in color gamuts for that. For many colors, the shift is slight – for others it can be significant. Designers and printers should be able to show you both color swatches of the PMS color you chose, and of any color shift that will occur from switching to the CMYK equivalent of that color.

And not to make things seem even harder, but color perception is also influenced by a host of other issues. The type, color and material of substrate you are printing on can vastly alter certain colors. Specialty finishes like gloss overlaminates or UV coating can as well. Screen calibrations of monitors used in the design and proofing process can influence how colors appear, and the lighting where any screen or print is viewed is also a factor.

One more interesting phenomenon: metamerism. Without getting into the science behind the term, some colors that are actually different will appear identical to the human eye under certain lighting conditions and different under others. There are at least 12 conditions that can create this metamerism: light, angle of view, size, distance, time, scenery, gloss… even differences in the human eye itself. 

So what about that problem with dark blues? If you are using blue in your logo or designs, and are concerned about a color shift toward purple, be certain that the cyan and magenta values in the CMYK definition of your blue color vary by at least 30% (some recommend 40%). Anything less than that, especially with dark colors, and the blue and red will mix to render purple – it is just a fact of physics. 

Knowing these types of technical color issues is important if you choose to buy your print online from a large, bulk print provider. They will print exactly what you sign off on when you submit your file. When you work with your local printshop, a good relationship between you, your designer, and your printer will bring you a team approach to getting the exact color you want on all your valuable marketing.  

Call us at 828.684.4512 for any marketing needs. As a printer, we understand communication, design, and teamwork. Your printer should be able to provide you with the latest information, inspiration, technical advice, and innovative ideas for communicating your message through print, design and typography, signage, apparel, variable data printing and direct mail, integrated marketing and environmentally responsible printing. If they can’t, you have the wrong printer! The best advice, always, is to ASK YOUR PRINTER!

ImageSmith is now partnered with Extreme Awards & Engraving – our in-house partner providing custom engraved trophies and awards for employee recognition programs, sporting events, and promotional needs. With our new sister company, we will be sharing space, resources and expertise in a collaboration designed to further provide you with one place to meet all of your marketing needs… Under One Roof! Visit them online at www.extremeae.com or call direct at 828.684.4538.

 

ImageSmith is a full-service print and marketing provider located in Arden, North Carolina. Contact us at ImageSmith for quotes on all your print and marketing projects, and more useful tips on how to create custom, effective, high impact marketing solutions.

Gradient Banding in Wide Format Printing: Can You Prevent It?

 

A quick check online convinces me that a lot of folk – designers, artists and printers – are frustrated with gradients that print with banding, or clearly dileneated “steps” of color visible in both digital and offset printing and which can be even more dramatic in wide format output. The bottom line is that those sweet gradient tools in your design software do not come with warning labels to prepare you for the resulting output in print. Gradients will normally (but not always) look good onscreen, but the technology to print them with similar ease falls short. The current best solution is to apply PhotoShop effects to minimize or hide the banding. The drawback is just like a great medication with a not-so-great side effect, this can produce unwanted results: colors can shift and the image may print “grainier” than originally planned.

A radial gradient should ideally look smooth, like a sunburst. The sample below, however, shows how it generally prints like the Looney Tunes logo.

banding problems in gradient printing

 

 

 

There is no fix for the banding problem when saving your Illustrator files. We’ve often searched for that magic button, with no luck. Below are a few photos from a recent experiment where a stubborn orange-to-yellow gradient in a client’s wide format pop-up display printed with visible, distracting banding regardless of file type, compression or other options used. Saving the file as eps, pdf, opening in PhotoShop, increasing resolution, optimizing with PitStop…. no luck. Each resulted in the same diagonal “steps” in color.

banding in gradient printing

 

The reason these efforts fail lies in mathematics and the physics of print, and I will admit to having only a shady understanding of these technical causes. For the scope of this post, let’s just point out that there are only so many “shades” or steps between one color and the next that are renderable in print. Your goal is to make a smooth transition from one color to the next, and the CS software makes that very easy in the design phase. However, the factors at play when you try to print your creation are the size or amount of space over which that transition occurs on the printed piece, the colors you have chosen to blend, and the resolution of the printer. Mathematically, at some point the printer has to go from one “step” to the next – and often the result to the human eye are bands or lines at which those changes occur. If you have chosen colors that are close together, you have even fewer “steps” between them with which to work. While PhotoShop, Illustrator and InDesign generally render smooth gradients onscreen, the science behind image rasterization and both offset and digital printing is not so forgiving to the viewer.

The fix for our wide format print in this case was to take the gradient portion of the job into Photoshop (it was originally created in Illustrator, we think!) Step one: we applied a Gausian Blur. The amount? Well that completely depends on the image. I just decide visually, bearing in mind whether or not the image I am working on is viewed at full-size onscreen or will be enlarged when printed out. A small grain visible now will be twice as large if printed at 200%. Next we created a layer with the mode set to Overlay and checked the box “Fill with Overlay-neutral color (50% gray).” To this layer we added Noise. Again – I decide visually how much noise to use (that’s an odd statement if you think about it!). Unfortunately, it is a guessing game, but with experience you will know best how much “graininess” or added texture will be acceptable without being enough to distract or compromise the output image.

Overlay mode in PhotoShop to prevent banding of gradients

gradient banding, Illustrator Photoshop InDesign

The result here was a minor shift in colors and a slight visible texture or graininess that wasn’t there before. But both served to hide the banding problem! Both were acceptable results as the overall appearance of the gradient was smooth and pleasing.

Tips to prevent or minimize banding in gradients are easy to find online, but often your individual design is built in such a way that many of the tips seem unworkable. Like ours, the most common banding-buster tips require you create (or recreate) your gradient in PhotoShop as we did above, and then add noise to the image. However, you might have other elements in your design such as type, vectors or other effects applied in either Illustrator or InDesign which prevent you from moving the entire file into PhotoShop. If the file has been received from another person or client, then you might not have access to the individual pieces of the file and would be stuck trying to put the entire document into PhotoShop as an image in order to play around with possible filters. Apparently there is no “one size fits all” fix for this frustrating problem. Designers should be aware that gradients present difficulties and often require cooperation with your printer ahead of time to avoid unpleasing results.

 

 

Printers understand communication and design. Your printer should be able to provide you with the latest information, inspiration, technical advice, and innovative ideas for communicating your message through print, design and typography, signage, apparel, variable data printing and direct mail, integrated marketing and environmental responsible printing. They should also be able to work with you to solve any difficult prepress issues with your files. If they can’t, you have the wrong printer! The best advice, always, is to ASK YOUR PRINTER!

Call us at 828.684.4512. ImageSmith is a full-service print and marketing provider located in Arden, North Carolina. Contact us at ImageSmith for quotes on all your print and marketing projects, and more useful tips on how to create custom, effective, high impact marketing solutions.