Pierre Urbain

Abstract

Today, conventional printing processes such as offset lithography, gravure and flexography are not the only processes available to satisfy the print buyers' needs. Digital printing is now able to rival offset quality, and has taken a substantial position in the commercial and publication printing market. Conventional printing technologies have been extensively studied and standardized. The principal international standards for conventional technologies, the ISO12647 series, specify aims and tolerances that are process based. Digital printing is more difficult to standardize because its diversity of technologies and consumables make the creation of process-based aims nearly impossible. A new approach to standardization, conformance to dataset, is emerging and offers the opportunity to overcome the problems associated with standardizing digital printing. In this approach, the focus of conformance shifts from the process to the product, and, as a result, conformance is independent of the process used to produce the product. The recently published CGATS TR016 provides a methodology and tolerances for assessing conformance to dataset. The tolerances in TR016 were developed using a sheet-fed offset printing database. This research assesses the ability of digital production presses to meet TR016 tolerances. In order to assess the ability of digital production presses to meet TR016 tolerances, it was first necessary to enroll digital printers who were willing to prepare samples for assessment. A total of four printers in Europe and in the USA were enrolled and printed testforms were collected from nine electrophotographic digital presses. These testforms were send to RIT and measured on a single instrument to insure data consistency. The measurements obtained were assessed for conformance to TR016 tolerances and, finally, passing probabilities for digital production presses were compared to the offset passing probabilities provided in TR016. For the digital presses sampled, within-sheet variation passing probabilities closely matched within-sheet passing probabilities for offset. Within-run repeatability for these digital presses was excellent. The major difference between digital passing probabilities and offset passing probabilities was found to be in the area of deviation conformance. Because digital presses frequently print on heavily OBA loaded paper, conformance to TR016 deviation tolerances is sensitive to the use of substrate corrected colorimetric aims. Not all printers sampled were familiar with this technique, and this lack of familiarity affected the deviation results obtained. In addition, digital front end (DFE) software was shown to have a significant effect.

Library of Congress Subject Headings

Digital printing presses--Quality control; Digital printing--Standards

Publication Date

4-26-2012

Document Type

Thesis

Department, Program, or Center

School of Print Media (CIAS)

Advisor

Eller, Robert

Comments

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: Z249.3 .U73 2012

Campus

RIT – Main Campus

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