scholarly journals Automated CtP Calibration for Offset Printing : Dot gain compensation, register variation and trapping evaluation

2015 ◽  
Author(s):  
Shahram Hauck
Keyword(s):  
Offset Printing ◽  
Register Variation ◽  
Dot Gain ◽  
Gain Compensation

A Study of Color Variance between Vacuum Plate of Aluminum and Aluminum Foil Using UV Offset Printing

2012 ◽  
Vol 262 ◽  
pp. 253-257
Author(s):  
Chang Lang Chen ◽  
Mei Chun Lo ◽  
Ming Chw Wei ◽  
Shi Wei Wang
Keyword(s):  
Aluminum Foil ◽  
Packaging Materials ◽  
Offset Printing ◽  
Color Gamut ◽  
Test Form ◽  
White Board ◽  
Printing Quality ◽  
Dot Gain ◽  
Green Packaging ◽  
The Difference

In packaging market, Vacuum Plate of Aluminum by UV offset printing is light impediment effectively, moisture-proof, and forgery-proof and reaches the request of the green packaging production. Thus, the packaging of Vacuum Plate of Aluminum is used widely. This study was a true experimental research. The test form employed was the printing quality control strip from international printing specification. It was used to record and analyze the color variance between Vacuum Plate of Aluminum and Aluminum Foil with white board and no white board using UV Offset Printing. The study indicated the comparison of Tone Value Increased & the difference of Color Gamut Range among these three packaging materials via C, M, Y, K four colors tone value and RGB area testing, and results reveals that the tone value on the Vacuum Plate of Aluminum with white board increased most among these three materials; the dot gain percentage of the Vacuum Plate of Aluminum is less than 15% which with the highest stability than others. All signature findings are given in Fig.1 and Fig.2. These results are entirely consistent with research hypotheses.

Research on the Relationship between Ink Permeability and Dot Gain of Different Paper

2013 ◽  
Vol 469 ◽  
pp. 318-321
Author(s):  
Yu Xiu Wang ◽  
Guang Xue Chen ◽  
Qi Feng Chen ◽  
Jing Lei Tai
Keyword(s):  
Offset Printing ◽  
Coated Paper ◽  
Dot Gain ◽  
Printing Paper ◽  
Inkjet Printer ◽  
The Relationship

In order to research the relationship between ink permeability and dot gain of different paper, four kinds of coated paper and two kinds of printing paper were chosen. Ink marks method was used to measure ink permeability of four kinds of coated paper and two kinds of common printing paper. After the ink marks were printed on each of the six kinds of paper, the length of them were measured, then the reciprocal of the ink marks length was multiplied by 1000 to obtain the value of the ink permeability. Inkjet printer was also used to print yellow GATF step-wedge simulating offset printing on the six kinds of paper, then using an optical densitometer to measure the dot gain. Conclusion shows that non-coated paper is higher in permeability than coated paper, which results in high percentage of dot gain.

Research on Dot Gain Compensation Curve Algorithm Model

2012 ◽  
Vol 200 ◽  
pp. 627-631 ◽  
Author(s):  
Li Li Si ◽  
Feng Xian Sang ◽  
Zhen Liu
Keyword(s):  
New Method ◽  
Average Error ◽  
Dot Gain ◽  
Gain Compensation ◽  
Normal Method ◽  
Compensation Curve

To make the dot gain compensation curve more precise, this paper analyzes the methods already used and then propose a new method. We implement this new method and the old ones respectively through MATLAB, and get their dot gain compensation curves. At the same time, the average error and variance were counted to test their precision. The results show that the new method can apparently improve the precision and reduce the error. The average error of the normal method is 2.96% while it is reduce to 1.56% by the new method.

Classified Quantization Research on Dot Gain Characteristic

2014 ◽  
Vol 596 ◽  
pp. 417-421
Author(s):  
Qi Wang ◽  
Qian Wang ◽  
Xiao Lin Qiu ◽  
Tian Ma Wang
Keyword(s):  
Light Scattering ◽  
Scattering Function ◽  
Offset Printing ◽  
Function Model ◽  
Dot Gain ◽  
Printing Ink ◽  
Gain Characteristic

Dot gain divides into physical and optical dot gain. These two parts constitute the comprehensive dot gain in the process of printing. Ink spreading on the surface of paper is used for the analysis of physical dot gain and light scattering function model is used for optical dot gain. Trace the dots on the CTP plate and offset printing proof to analyze the influence of image micro-parameters caused by dot gain. Physical and optical dot gain are quantized to research the correlation between dot gain and shape of dot. It shows that: optical dot gain of AM dot accounts for a larger proportion; dot gain of all types has no relation with shape of dot. Besides, physical dot gain of FM dot accounts for a larger proportion than optical dot gain.

Research on the Method of Determining the Optimum Parameters for Offset Ink

2010 ◽  
Vol 174 ◽  
pp. 255-258
Author(s):  
Wen Yan Jiang ◽  
Zhi Hong Wang
Keyword(s):  
Process Control ◽  
Experimental Method ◽  
Printing Process ◽  
Tone Reproduction ◽  
Optimum Parameters ◽  
Calibration Curves ◽  
Printing Quality ◽  
Dot Gain ◽  
Gain Compensation ◽  
The Relationship

By experimental method, the optimum parameters for offset ink were investigated under standard printing conditions. Firstly, the relationship between solid ink density and print contrast was established, and the optimum values of solid ink densities and print contrasts were calculated. Then, perfect tone reproduction was achieved by dot gain compensation, in which the calibration curves were obtained by the target curves and the initial tone value increase(TVI) curves based on optimum SIDs. The results showed that this method of determining the optimum parameters for offset inks were practicable and reliable, it can be used to research the printability of inks and papers, optimize printing process, improve printing quality, and provide method of standardization of process control for printing institutions.

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

Use of confocal laser scanning microscopy and a computer model to understand ink cavitation and filamentation

TAPPI Journal ◽  
2010 ◽  
Vol 9 (10) ◽  
pp. 7-15
Author(s):  
HANNA KOIVULA ◽  
DOUGLAS BOUSFIELD ◽  
MARTTI TOIVAKKA
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Print Quality ◽  
Length Scale ◽  
Offset Printing ◽  
Significant Difference ◽  
Printing Speed

In the offset printing process, ink film splitting has an important impact on formation of ink filaments. The filament size and its distribution influence the leveling of ink and hence affect ink setting and the print quality. However, ink filaments are difficult to image due to their short lifetime and fine length scale. Due to this difficulty, limited work has been reported on the parameters that influence filament size and methods to characterize it. We imaged ink filament remains and quantified some of their characteristics by changing printing speed, ink amount, and fountain solution type. Printed samples were prepared using a laboratory printability tester with varying ink levels and operating settings. Rhodamine B dye was incorporated into fountain solutions to aid in the detection of the filaments. The prints were then imaged with a confocal laser scanning microscope (CLSM) and images were further analyzed for their surface topography. Modeling of the pressure pulses in the printing nip was included to better understand the mechanism of filament formation and the origin of filament length scale. Printing speed and ink amount changed the size distribution of the observed filament remains. There was no significant difference between fountain solutions with or without isopropyl alcohol on the observed patterns of the filament remains.

Sign in / Sign up

Export Citation Format

Share Document