A Horse Of A Different Color...learn how colors can change in appearance under different lighting conditions.
A customer had encountered a problem whenever she printed
grey. When the prints were viewed inside, the color was dead on.
But viewed outside, in the sun the grey immediately turned green. The
other day she printed a beautiful grey horse and laminated it. As soon as the
print was viewed outside, the grey took on a green tint. Was this a problem
with the laminate? Not necessarily.
Colors can change in appearance under different lighting
conditions. To understand how, let’s first explain the concept of reflected
color. The color that we perceive is light that reflects off the object that we
are viewing. White light, which is the combination of all wave
lengths of color, travels through the transparent inks (cyan, magenta, yellow)
on the surface of the print. Some wavelengths of light are absorbed or
subtracted from the light as it passes through the ink. The remaining light
bounces or reflects off of the print media through the ink again and to our eyes. The receptors in our
eyes detect three of the frequencies of light: red, green and blue. Our brain
responds to the messages from these receptors to create our perception of
color.
The ink colorants on the surface of a print certainly are
important to the color that we see. But there are a couple of other factors
that affect the perceived color. One factor is the color of the
substrate. Printers know that white is not white is not white.
That’s why white substrates are rated in terms of their brilliance. An
even more important factor, however, is the light that reflects off of the
print.
In a perfect world, the various
electromagnetic wavelengths that comprise light would all be at full intensity
to produce a pure white. Not too much in this world is perfect. Light can be
biased toward a certain part of the spectrum, and can impart a reddish,
yellowish, bluish or greenish cast to what we are viewing.
The light, that an incandescent light bulb with a tungsten
filament emits, for example, is yellowish. On the other hand, the light
from a fluorescent bulb can appear bluish or greenish. If you step outside,
natural light appears much different than either the tungsten light bulb or the
fluorescent lighting. And depending on the time of day, the lighting can
vary in color. Lighting at high noon is more of a purer white than
that when the sun is on the horizon.
These subtle changes in light may not be noticeable with the naked
eye, because our eyes tend to compensate for the variances. The result is
that for most people, white light will all appear the same. As for the object
that the light illuminates, these subtle variations in hue can stick out like a
sore thumb. This is why lighting makes color matching difficult,
frustrating and quite often time-consuming.
Photographers of old, who shot film, were
very aware of the quality of light. If you were photographing under
fluorescent light, and had film balanced for daylight, the resulting prints
would appear greenish.
Early in my indoctrination in the screen
print industry, I was taught to ask the client under which lighting conditions
would the graphic be viewed. Based on the application, colors were mixed
and matched against a color sample. To accurately compare the colors, samples
were viewed in a color light booth.
This light booth had several light sources
under which comparisons were made. I have seen two colors that appeared to
match perfectly under incandescent lighting, look very different when the light
was switched to artificial daylight. I have also seen one color look
darker than another under one type of light, suddenly appear lighter when the
light source was changed.
Obviously, most colors do not
radically change their appearance as the light source changes. Otherwise,
everybody would be aware of this phenomenon. Those colors that do change
dramatically are referred to as being metameric. To prevent metamerism from
occurring, manufacturers use additives to their ink formulas to prevent color
shifts. Just be aware that it is possible for colors to shift their hue
as light changes, and this is more common with neutral colors, such as grey.
Wet Applications. Dry applications are typically recommended for most vinyl applications. For those exceptions to the rule, this instructional video explains the right way to perform a wet application. Click to Link
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Vinyl Application Over Rivets. Applying vinyl graphics on vehicle surfaces with rivets is challenging for most sign makers. Vinyl failures to these surfaces are all too common. This video demonstrates some tips and procedures, used by professional decal installers, which will make these demanding applications easier and more trouble-free. Click to Link
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Applying Air Egress Vinyls. Vinyl films with air egress release liners have almost eliminated bubbles and wrinkles from applied graphics. Air egress release liners with their highly textured surface structure are problematic. Not much will stick to these liners other than the vinyl film. At RTape our best premask solution for air egress liners is a special Conform® tape called 4761RLA. Click to Link
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Wet Applications. Dry applications are typically recommended for most vinyl applications. For those exceptions to the rule, this instructional video explains the right way to perform a wet application. Click to Link
Application of Window Graphics. Installing vinyl graphics on glass can be challenging, because the adhesive aggressively grabs onto this high energy surface. Repositioning graphics on window is generally difficult, if not impossible. This instructional video explains how to dry apply window graphics right the first time. It also describes the necessary steps required for surface preparation. Click to Link
Transferring Frosted Window Graphics Films. Because frosted window films are highly textured, transferring cut vinyl graphics can be problematic. This video provides direction in selection of the right application tape and how to apply these films quickly, easily and without problems. Click to Link
3-Step Surface Prep. This instructional video describes how to properly clean the surface of a vehicle before applying pressure sensitive vinyl graphics to a trailer or doing a full wrap of a car or van. This three step surface prep involves detergent washing, solvent cleaning and a final wipe down with IPA. Click to Link
Vinyl Application Over Rivets. Applying vinyl graphics on vehicle surfaces with rivets is challenging for most sign makers. Vinyl failures to these surfaces are all too common. This video demonstrates some tips and procedures, used by professional decal installers, which will make these demanding applications easier and more trouble-free. Click to Link
Vinyl Application to Corrugations. Learn how to apply vinyl graphics to corrugations in a relaxed state. Forcing films into the valleys of corrugations puts too much mechanical stress on the film. Sooner or later, the vinyl will lift or tent in valleys. Click to Link
Applying Air Egress Vinyls. Vinyl films with air egress release liners have almost eliminated bubbles and wrinkles from applied graphics. Air egress release liners with their highly textured surface structure are problematic. Not much will stick to these liners other than the vinyl film. At RTape our best premask solution for air egress liners is a special Conform® tape called 4761RLA. Click to Link
About Jim Hingst: After fourteen years as Business Development Manager at RTape, Jim Hingst retired. He was involved in many facets of the company’s business, including marketing, sales, product development and technical service.
Hingst began his career 42 years ago in the graphic arts field creating and producing advertising and promotional materials for a large test equipment manufacturer. Working for offset printers, large format screen printers, vinyl film manufacturers, and application tape companies, his experience included estimating, production planning, purchasing and production art, as well as sales and marketing. In his capacity as a salesman, Hingst was recognized with numerous sales achievement awards.
Drawing on his experience in production and as graphics installation subcontractor, Hingst provided the industry with practical advice, publishing more than 150 articles for publications, such as Signs Canada, SignCraft, Signs of the Times, Screen Printing, Sign and Digital Graphics and Sign Builder Illustrated. He also posted more than 325 stories on his blog (hingstssignpost.blogspot.com). In 2007 Hingst’s book, Vinyl Sign Techniques, was published. Vinyl Sign Techniques is available at sign supply distributors and at Amazon.
© 2016 Jim Hingst
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