Best Practice: Fluorescent Inks in Spot Color and ICC Workflows

Applies to: Ergosoft RIP 17 and later · ColorGPS (multicolor), Named Colors · printers with visible fluorescent (neon) inks, for example fluorescent yellow or fluorescent pink

Use this when:

You want fluorescent effects for specific design elements
You want brighter, more saturated colors in all designs, not only in spot color areas
Your ColorGPS profile uses the fluorescent ink less than expected

Goal

Use fluorescent inks in two ways: as spot colors for dedicated effects, and as additional ICC profile channels for a larger gamut. Choose the workflow per design, or combine both.

Fluorescent (neon) inks absorb invisible UV light and re-emit it as visible light. The colors look as if they are lit from within and reach areas that CMYK cannot print. They work best on a bright white media, for indoor or short-term graphics.

Recommended Tools

Tool	Purpose in this workflow	Where to Find It
Ink Assignment	Defines whether the fluorescent ink is a spot color or an additional profile channel	Print Environment Settings > Ink Assignment
Named Colors	Stores a fixed recipe for each spot color in the Print Environment	Tools > Color & Special Features > Named Colors...
ColorGPS	Creates the ICC profile with the fluorescent inks as additional profile channels	ColorGPS
ICC Color Usage and Limit	Controls where ColorGPS uses each additional profile channel	ColorGPS > Options > ICC Color Usage and Limit...
Job Gradation Curves	Quick check of how much of each ink channel the profile uses	Job Properties & Actions > Job Gradation Curves

Workflow

Step 1: Choose the Workflow per Design

Design	Workflow
Contains named spot colors for fluorescent effects	Spot color workflow (Step 2)
Photos or designs that need brighter colors in general	Fluorescent inks as ICC profile channels (Steps 3 and 4)
Both	Hybrid workflow (Step 5)
Invisible fluorescent ink (glows only under UV light, for example for security prints)	Spot color workflow only (Step 2). Invisible inks cannot be measured, so they cannot be ICC profile channels.

Step 2: Spot Color Workflow

In Ink Assignment, assign the fluorescent ink to a spot color slot, for example Spot Color 1.
Check that the design contains a named spot color for each fluorescent effect (EPS or PDF).
Open Named Colors, add the spot color name, and set the Print Color Value to 100% of the fluorescent ink channel.

Result: The spot color areas print with the fluorescent ink only.

Step 3: Fluorescent Inks as ICC Profile Channels

In Print Environment Settings > Ink Assignment, select a profile channel for each fluorescent ink, for example Profile channel 8 (P8) and Profile channel 9 (P9). With a profile channel, ColorGPS includes the ink in the profiling. To change the display name and the preview color, for example to "Fluo Yellow", click the color field.
Run the Density Linearization, including the fluorescent channels.
Create the profile in ColorGPS. Start with the factory defaults.

Result: The profile uses the fluorescent inks in their hue range, for example for bright yellows, oranges or pinks. No designer work is needed.

Fluorescent inks as primaries: some drivers let you use the fluorescent inks as primaries, for example fluorescent pink instead of magenta. Check the device options of the driver.

	Fluorescent inks as primaries
Pros	ColorGPS uses the fluorescent inks more, even with the default restrictions. The prints look brighter from the start.
Cons	The fluorescent inks are also used for the black generation, so the gray axis can be less neutral. Prints fade faster over time, because the fluorescent inks are in almost every color.
Recommendation	In ColorGPS, set Black generation to GCR1 or GCR2 to reduce the effect on the gray axis.

Important: Measure all charts with M0 or M1, and use the same condition for the Density Linearization and ColorGPS. Do not use M2 (UV cut): it removes the UV part of the light, so the measurement misses the light that the fluorescent inks re-emit.

Step 4: Adjust Where ColorGPS Uses the Fluorescent Inks

ColorGPS reserves an inner area of the gamut for the primaries (CMY), so that gradients stay smooth. Bright, saturated additional colors are barely affected by this restricted area. If the fluorescent ink is used less than expected, adjust the restriction:

In ColorGPS, go to Options > ICC Color Usage and Limit....
Under Color, select the fluorescent channel. The settings apply to each additional profile channel separately.
To allow the fluorescent ink in more colors, enable Soften color restrictions and enter a percentage. 0% = normal restrictions. Higher values shrink the restricted area, so ColorGPS also uses the fluorescent ink in less saturated colors.
To keep the fluorescent ink out of dark colors, clear No lightness limit and set Min L, for example 30. ColorGPS then does not use the ink in colors darker than L 30. A Max L limit can help if the ink causes visible dots (graininess) in light tones.
Generate the profile again. You do not need to print or measure a new chart.

The illustrations show an additional orange ink. The blue area is restricted to the primaries. Top: factory defaults (0%). Bottom: Soften color restrictions 50% – the restricted area is smaller, and ColorGPS uses the additional ink in more colors.

Note: Values above 100% are not recommended. At 200%, the restricted area is gone: ColorGPS treats the additional ink like a primary and uses it wherever it fits, which can affect smooth gradients and neutral tones.

With Min L 30, ColorGPS does not use the fluorescent yellow in colors darker than L 30:

Check the result:

Job Gradation Curves > Auto Vibrancy: the proposed curve shows how much of each channel the profile uses. A large distance to 100% means there is room to soften the restriction.
Job Preflight (separated) or a printed color book: compare the fluorescent channel before and after the change.
Color Picker: compare the output recipes of the same color.

Step 5: Hybrid Workflow

Use the Print Environment with the fluorescent profile channels (Steps 3 and 4) as the default.
For designs with fluorescent spot colors, also use Named Colors or spot color replacement (Step 2) with the same Print Environment.

Result: The ICC profile already uses the fluorescent inks for all colors. Dedicated effects print with the recipe of the spot color, for example pure fluorescent ink.

Why This Works

A spot color workflow gives full control over specific areas, but needs named colors in the design. An extended-gamut profile uses the fluorescent inks automatically in every design. ICC Color Usage and Limit is part of the profile: once set, it applies to every job with this Print Environment. Job Gradation Curves can give a similar effect faster, but they reduce color accuracy.

Limitations

Fluorescent colors look different under different light sources. A measurement describes the visual effect only partly.
Fluorescent inks are less lightfast than standard inks and fade faster in direct sunlight. The more fluorescent ink a profile uses (lower restrictions, fluorescent primaries), the stronger the effect over time.
Lower restrictions use more fluorescent ink. Check gradients and neutral tones after each change.

FAQ

Do I need special artwork for the ICC workflow?
No. The profile decides where to use the fluorescent inks. Named spot colors are only needed for the spot color workflow.

Can ColorGPS handle a fluorescent ink next to a regular ink of the same hue?
Yes. ColorGPS supports inks in the same hue range as separate profile channels.

Can I use invisible (UV-only) fluorescent inks in the ICC profile?
No. They cannot be measured in normal light. Use them as spot colors (Step 2).

Do I need a new chart after I change ICC Color Usage and Limit?
No. The setting changes the profile calculation. Generate the profile again from the same measurements.

Spot Colors / Named Colors (User Guide)
Create Color Profiles in ColorGPS (User Guide)
Why Does ColorGPS Use Dynamic Profiling Charts Instead of IT8?
Density Linearization (User Guide)
Color Replacement Introduction

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References

Changelog #16039 – Ergosoft RIP 17.7.2.0465: a driver with fluorescent pink and fluorescent yellow offers device options that define how the fluorescent inks are used (for example as primaries).
Changelog #15503 – Ergosoft RIP 17.7.2.0465: spot color replacement for pixel image formats (TIFF, PSD, PSB) has been unified with vector formats (PDF, EPS).

Fluorescent Inks: Spot Color and ICC Workflows