1. The Effects of Clear Toner on the Color Gamut of a Digital Press
Robert Grotans
Western Michigan University
December 7, 2010

2. Overview
Background
Experimental
Results
Conclusion

3. Understanding Color
Illuminant + Sample Spectrum + Standard Observer

4. What is “Color Gamut”?
1931 x, y Chromaticity Diagram

5. Profiling 1. Calibrate your device
2. Print, display, or scan a test chart
3. Measure the test chart
4. Use profiling software
5. Produce a profile

6. Experimental List of Substrates Substrate Name GSM 1
20# Hammermill Bond 75 2
24# Beckett Writing (super smooth) 90 3
60# Husky Opaque Offset 89 4
60# 4CC Storaenso Cover
160 5
80# Sappi Flo Gloss Digital Text
118

7. 1. Calibrate The Device Shading Correction Gradation Auto Adjust
Fiery RIP Calibration

8. 2. Print a Test Chart
ECI2002R CMYK test chart

9. 3. Measure the Test Chart

10. 4. Use Profiling Software

11. 5. Produce a Profile
Install profile
Verify profile for accuracy

12. Analysis Gamut Comparison LAB Value Comparison (39.79, 15.83, 18.12)
(44.01, 16.07, 17.5)

13. GretagMacbeth™ ColorChecker

14. Calculations ΔE = √(L1-L2)2 + (a1-a2)2 + (b1-b2)2 ΔL = (L1-L2)
= √(39.79-L2)2 + (15.83-a2)2 + (18.12-b2)2
= √( )2 + ( )2 + ( )2
ΔE = 4.27
ΔL = (L1-L2)
=( ) = -4.22
ΔC = √(a12+b12) - √(a22+b22)
= √( ) - √( (-17.5)2) = 0.3

15. Sample 1 – 20# Hammermill Bond
Without 312,879
With 228,669

16. Sample 2 – 24# Beckett Writing
Without 322,846
With 255,525

17. Sample 3 – 60# Husky Offset
Without 338,949
With 239,272

18. Sample 4 – 60# Cover
Without 404,957
With 267,681

19. Sample 5 – 80# Gloss Text
Without 330,186
With 242,463

20. Clear Toner Over Vs. Clear Toner Under
LAB Values
Clear Toner Over Vs. Clear Toner Under
Substrate ΔE ΔL ΔC 1
3.18
-1.87
1.08 2
2.47
-1.19
0.31 3
1.54
-0.06
0.17 4
3.11
-1.88
0.74 5
2.15
-0.58
1.15

21. Without Clear Toner Vs. Clear Toner Over
LAB Values
Without Clear Toner Vs. Clear Toner Over
Substrate ΔE ΔL ΔC 1
4.78
-0.59
-3.20 2
4.60
-2.46
-3.01 3
7.22
-1.65
-4.29 4
6.86
-1.74
-3.68 5
4.75
-1.42
-2.81

22. Conclusion Not a lot of difference between clear toner over or under
Clear toner originally reduced the color gamut by 20-35%
Knowledge gained
Recommendations
Paper
Original Clear Toner
New Clear Toner
94.7, 2.1, -7
88.3, 1.8,-6.2
92.1, 2.1, -6.7

23. Special Thanks Mark Gundlach and Michelle DeFouw, X-Rite Dr. Fleming
PCI Department

24. Thank You!
Questions?