Agency designers want to create a large thermochromic ink feature for a CPG candy package redesign focused on putting the candy in the refrigerator until it’s deliciously cold. When the package changes color, that’s the cue to enjoy it.

“Can you give us a color palette with numbers for the thermochromic ink?”

Well ... sort of.

If you’ve ever held up a thermochromic or photochromic printed sample to a color standards book to get the reference color number, chances are that it’s close, but not quite. On CTI color sheets, we say that the values are approximate, not exact.

Why?

First off, color standard swatch books revolve around spot colors and CMYK colors made from common pigments. That’s why there’s a Red 185 and a Reflex Blue. Mix the pigments get the same color every time.

Secondly and related, thermochromic and photochromic inks use different dyes, which have different hues than the standard pigments used for color standard swatch books.

Lastly, the color and intensity of thermochromic and photochromic inks depend on the printed coat weight. These translucent dyes do not give opacity like standard pigments, so printers and converters should follow several guidelines for strong color:

• Optimal graphic design: Specialty temperature- and light-activated inks should be used in large, solid areas for best effect. Avoid screen values of less than 60%.

• Heavy aniloxes and cylinders: To get the needed film weight, use a 7 BCM or greater anilox for Flexo presses and a 130 or greater diamond stylus for Gravure presses.

• More than one print station: When using offset and water-based inks, you may need more than one print station, i.e., two or more hits of thermochromic or photochromic ink, to achieve color.

CTI’s new solvent-based thermochromic, photochromic and glow-in-the-dark inks give printers and converters excellent options for strong color, easy operation and outstanding print quality, not to mention superior mileage over water-based Flexo and Gravure inks.

Regardless of what print format you’re running, CTI has the industry’s best solutions, design and technical expertise and large format printing experience to help you see the best results and give customers amazing visual experiences.