A Designer\u27s guide to the evaluation of digital proofs

Digital color proofs and pre-proofs are used by graphic artists and commercial printers throughout the prepress process. However the prepress process has undergone radical changes over the past decade due to the introduction of desk top publishing and desktop prepress. Alongside of the desktop publishing revo lution has come a multitude of new digital proofing technologies for use in this ever changing environment. Technologies including, but not limited to, liquid inkjet, dye sublimation, continuous inkjet, color laser, and thermal wax transfer printers have provided an entire range of color accuracy and price suitability to many of their users. However one needs to be able to understand the practical applications and limitations of these technologies to make a suitable choice for a specific prepress operation or design process. Therefore a handbook for the users of digital proofs has been created for their benefit. The underlying structure of this handbook is based on the following six chap ters. The first chapter, entitled Communicating with Prepress and the Attributes of Digital Proofing, contains multiple parts. Firstly, it contains information for the designer in regards to the advantages and disadvantages of all types of digital output devices. It discusses the advantages which digital output devices may or may not have over conventional proofing systems. Additionally, ideas such as the vantages and drawbacks of preproofers and proofers is elaborated upon. Information for this part of the chapter was obtained through questionnaires completed by, and interviews with print buyers, art directors, and production managers from advertising agencies and prepress providers in the Rochester area. More information for this section of the first chapter was obtained through various manufacturer\u27s literature, printing industry reports and various periodi cals. Chapter One also discusses ideas behind the application of color printers (preproofers) and digital proofers. These ideas address issues which pertain to the application of specific printing and proofing processes to specific phases of the creative and production processes. Additionally, discussions regarding proof ing costs, qualities, and production turnaround time may be found in this part of the first chapter. Information for this section of Chapter One was obtained through information found in printing and publishing related periodicals, as well as in manufacturers\u27 literature. Finally, the first chapter develops a system for the correction of digital preproofs and proofs. Multiple groups of ideas pertaining to the correction of digital output are discussed. Some of these include sections entitled Digital File Tracking and Identification, Evaluation of Design Elements, Evaluating Colors, Element Positioning, and Element Dimension Adjustments. Information for this part of the chapter was obtained through the evaluation of previously corrected digital con tract proofs and preproofs, as well as the interviews and questionnaires men tioned above. The second chapter, entitled Proofing Typography, displays the many different ways that printing and proofing technologies affect text type and display typog raphy. Using the CD-Rom included in the back of the book, one may view on screen how the following technologies affect type ranging from 3 points to 72 points in size: liquid inkjet, large format liquid inkjet, phase-change inkjet, ther mal wax transfer, dye sublimation, continuous inkjet, and dye ablation. Information and samples for this chapter were obtained through printing and proofing system manufacturers and advertising agencies in the Rochester area. The Color Primer and Chapter Three: Proofing for Imagery and Color, contain information for the designer which may be applied to proper evaluation of color on color prints and digital proofs. The Color Primer discusses subjects such as color space, the additive and subtractive color theories, and common color mea surement tools. Chapter Three then applies some of this knowledge in its discus sions of proper lighting conditions for viewing prints and proofs, and different human factors which influence the highly subjective evaluation of all digital color output. Information for this chapter was gathered using graphic arts and printing industry related periodicals and industry-wide books related to color and its reproduction. The fourth chapter, entitled Substrates and Digital Output, educates the design er about the effects on text, imagery, and graphics which occur when creating digital prints and proofs on a variety of papers. Various paper surfaces such as gloss, semi-gloss and matte surfaces are addressed. The affects of colored paper on imagery and graphics are also elaborated upon. Additionally, printing and proofing processes are discussed in regards to the substrates that they accept for output. Information for this chapter was gathered through manufacturers\u27 litera ture and various industry related books and periodical articles. The Proofing Process Supplement was created to familiarize the designer with all currently popular forms of digital output technology. The process supplement discusses the imaging processes used by the following digital output technolo gies: liquid inkjet, phase-change inkjet, thermal wax transfer, dye sublimation, continuous inkjet, and dye ablation. Additionally, the supplement contains brief explanations regarding screening technologies. Information for the process sup plement was gathered through manufacturers\u27 literature, interviews with pre press providers in the Rochester area, and interviews with technical representa tives from the manufacturers of devices which use the above digital, color out put technologies. Chapter Five, entitled Image Fidelity, simply illustrates how all of the current ly popular printing and proofing technologies affect graphics and imagery. Using the CD-Rom included with the guidebook, the reader may view magni fied and normal views of printing and proof sample imagery. Information noted by the reader in the proofing process supplement may then be actively applied when viewing these samples. Information and sample prints for the fifth chapter were gathered from several manufacturers and advertising agencies in the Rochester area. The sixth chapter, entitled The Acceptance of Digital Contract Proofing, discusses a new definition of the contract proof in regards to the evolution of digital proof ing. This chapter provides ideas for the designer, art director, and print buyer to realize when considering the use of digital contract proofing. Several questions are raised concerning what requirements a digital contract proof must fulfill depending upon the areas of its application and any agreements between the designer and prepress provider regarding their specific definition of a digital contract proof. Additionally, specific advantages of digital contract proofs, such as their ability to fingerprint a press and/or press run, are discussed. Finally, a discussion pertaining to the education of all users of digital proofing technolo gies is presented to aid the overall acceptance of digital contract proofing. Information for this chapter was obtained through the extensive interviews of leading technical and product oriented representatives from the manufacturers of currently used digital contract proofing systems. Many conclusions have been reached with the completion of this guidebook. In brief, the first and most prominent conclusion which may be reached states that the acceptance of digital contract proofing lies within the education of all designers, art directors and print buyers about digital printing and proofing technologies. As the use of digital contract proofing grows, education and inter est by all creative professionals will orient them towards their use of digital proofing systems. The next conclusion which has been reached is that the proper application of color printers and digital proofers is of major importance for the designer due to the added flexibility and rewards which result from the use of digital color out put devices throughout the creative and production processes. Another conclu sion which may be reached is that the display of proofing and printing process effects on text, graphics, and imagery serves to directly inform the creative pro fessional how these elements may be distorted by the utilized output device. Knowledge gained by the creative professional in regards to these effects helps to answer many questions regarding print or proof quality and proper output device application. Finally, additional knowledge gained by designers which pertains to proper viewing of all color output, color theories, color measurement, and proofing sub strates helps them to better communicate with those prepress and print professionals involved in the production process

Preparation and optimisation of transparent conducting patterns using inkjet printing

Transparent conducting patterns (TCPs) are critical components that are required to be integrated into photovoltaic (PV) cells for energy harvesting. Among the manufacturing processes that are available for the deposition of TCPs onto various substrates, inkjet printing which can be categorised as an additive dispensing process has demonstrated its competitiveness by offering numerous advantages, including non-contact, high resolution, high printing speed, low cost and low material consumption. However, the present bottlenecks to be overcome for further take-up of inkjet printing technology imperatively demand the understanding of materials behaviour involved in the ink formulation and printing process. This thesis is dedicated to the elaboration of fundamental aspects of technical challenges that have been encountered in the uses of inkjet printing technology for the generation of TCPs, thereby optimisation of functional properties of the printed patterns can be achievable through the modification of inks and optimum parameters used in the printing process. [Continues.

Development of a novel series interconnect for thin-film photovoltaics

Thin-film photovoltaics (TF-PV) offer possible cost savings from reduced semiconductor usage compared to the incumbent crystalline silicon technology. During manufacture TF-PV devices are deposited onto a large glass panel and split into many, series interconnected, cells in order to obtain a useful electrical output. M-Solv has patented a novel process to do this series interconnection in a single step, One Step Interconnect (OSI), after the deposition of all layers. This has a number of benefits compared to the conventional process including, but not limited to, reduced capital cost by ~30%, reduced panel transit time and reduced energy usage. In this thesis OSI is introduced, the individual processes developed (laser scribing, inkjet printing of insulator and conductor) and working modules manufactured. The electrical performance of the manufactured modules compare favourably with reference material from the same deposition run and modules interconnected in the conventional way. Fill factor (FF) is the principle metric when determining the quality of series interconnection and very high FF, ~80%, have been shown by OSI cells. Preliminary lifetime testing guided by the IEC 61646 specification has been carried out and the results are promising with OSI cells surviving more than double the required number of thermal cycles from -40 to +85°C with no sign of performance degradation

An entrepreneurial framework for deciding on the implementation of large format digital printing internationally

This study focuses on entrepreneurs within the SME sector using large format digital printing (LFDP) because of the changes in technology that influences the decisionmaking processes of the entrepreneur in the purchasing of a new LFDP. These fast changes are likely to continue and can cause technologies to become obsolete overnight. The entrepreneurs within the LFDP industry find themselves in the midst of these fast changes and are faced with a dilemma. On the one hand, they need to make sure that the technology used produces consistent and quality products. On the other hand, the entrepreneur needs to ensure an optimal return on investments. From the literature and the findings of the study, the researcher recommends a change to an existing model on a consultant involvement purchase of high technology products, which is then adapted to integrate resource-forecasting areas together with timing and type of information required as well as external environment scanning. The existing model’s focus is on the individual’s ability to make decisions based on their own knowledge. However, by integrating technology forecasting components, and scanning the business environment and resource forecasting needed the decision-maker will be better equipped to make decisions that also takes into account the external environment. This will also allow them to plan and manage growth in a systematic way. Therefore the proposed model takes into account individual capabilities and technology forecasting components that can facilitate the decision-making process. The adapted model on decision-making clearly delineates that the combination of entrepreneurial qualities and technology forecasting techniques in the LFDP industry will ultimately assist the entrepreneur on various levels in deciding on a new LFDP

Advances in powder bed fusion 3D printing in drug delivery and healthcare

Powder bed fusion (PBF) is a 3D printing method that selectively consolidates powders into 3D objects using a power source. PBF has various derivatives; selective laser sintering/melting, direct metal laser sintering, electron beam melting and multi-jet fusion. These technologies provide a multitude of benefits that make them well suited for the fabrication of bespoke drug-laden formulations, devices and implants. This includes their superior printing resolution and speed, and ability to produce objects without the need for secondary supports, enabling them to precisely create complex products. Herein, this review article outlines the unique applications of PBF 3D printing, including the main principles underpinning its technologies and highlighting their novel pharmaceutical and biomedical applications. The challenges and shortcomings are also considered, emphasising on their effects on the 3D printed products, whilst providing a forward-thinking view

Printing conductive traces to enable high frequency wearable electronics applications

With the emergence of the Internet of Things (IoT), wireless body area networks (WBANs) are becoming increasingly pervasive in everyday life. Most WBANs are currently working at the IEEE 802.15.4 Zigbee standard. However there are growing interests to investigate the performance of BANs operating at higher frequencies (e.g. millimetre-wave band), due to the advantages offered compared to those operating at lower microwave frequencies. This thesis aims to realise printed conductive traces on flexible substrates, targeted for high frequency wearable electronics applications. Specifically, investigations were performed in the areas pertaining to the surface modification of substrates and the electrical performance of printed interconnects. Firstly, a novel methodology was proposed to characterise the dielectric properties of a non-woven fabric (Tyvek) up to 20 GHz. This approach utilised electromagnetic (EM) simulation to improve the analytical equations based on transmission line structures, in order to improve the accuracy of the conductor loss values in the gigahertz range. To reduce the substrate roughness, an UV-curable insulator was used to form a planarisation layer on a non-porous substrate via inkjet printing. The results obtained demonstrated the importance of matching the surface energy of the substrate to the ink to minimise the ink de-wetting phenomenon, which was possible within the parameters of heating the platen. Furthermore, the substrate surface roughness was observed to affect the printed line width significantly, and a surface roughness factor was introduced in the equation of Smith et al. to predict the printed line width on a substrate with non-negligible surface roughness (Ra ≤ 1 µm). Silver ink de-wetting was observed when overprinting silver onto the UV-cured insulator, and studies were performed to investigate the conditions for achieving electrically conductive traces using commercial ink formulations, where the curing equipment may be non-optimal. In particular, different techniques were used to characterise the samples at different stages in order to evaluate the surface properties and printability, and to ascertain if measurable resistances could be predicted. Following the results obtained, it was demonstrated that measurable resistance could be obtained for samples cured under an ambient atmosphere, which was verified on Tyvek samples. Lastly, a methodology was proposed to model for the non-ideal characteristics of printed transmission lines to predict the high frequency electrical performance of those structures. The methodology was validated on transmission line structures of different lengths up to 30 GHz, where a good correlation was obtained between simulation and measurement results. Furthermore, the results obtained demonstrate the significance of the paste levelling effect on the extracted DC conductivity values, and the need for accurate DC conductivity values in the modelling of printed interconnects

Troubleshooting Ink Jet Printing Of Cotton Substrates Using A Knowledge-based Expert System

(Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2012(PhD) -- İstanbul Technical University, Institute of Science and Technology, 2012Bu çalışmada, pamuklu kumaşların ink jet baskısında karşılaşılan hataların belirlenmesi ve çözülmesine yönelik uzman sistem geliştirilmesi amaçlanmıştır. Bu amaçla literatür detaylı olarak taranmış, bununla birlikte baskıda uzman kişilerle de tartışılarak ink jet baskıda sık karşılaşılan on üç hata belirlenmiştir. Bunlar, kafa sürtmesi, renksiz bölge, yanlış renkli bölge mürekkep damlası(mürekkep lekesi), enine çizgilenme, çarpıklık, boya akması, desen kayması, kumaş sararması, düşük sürtme haslığı, düşük yıkama haslığı, renk şiddeti farklılığı/ton farklılığı, düşük keskinlik, beyaz veya solgun bölge olarak adlandırılmıştır. Daha sonra bu hataların nedeni olabilecek altmış bir adet sebep, detaylı literatür taraması ve yine uzman kişilerle yapılan görüşmeler sonunda belirlenmiştir. Bu hatalarla sebepler arasındaki ilişkiyi belirleyebilmek amacıyla uzmanlara sormak üzere anket hazırlanmıştır. Ankete katılan uzmanların her bir hata ile her bir sebebin ilişkisini beşli likert skalası kullanarak belirlemeleri istenmiştir. Ankete katılan bütün uzmanların cevap sayıları dikkate alınarak her bir hata ve altmış bir sebep arasında sayısal bir ilişki kurulabilmesi amacıyla çeşitli istatistik yöntemlerinden yararlanılmıştır. Sonuç olarak, sisteme entegre edilen çıkarım motorunun hataların sebeplerini ortak sebeplerden başlayarak belirlemesiyle iyi bir performans ortaya koymuştur. Ayrıca, sistem ink jet baskıda karşılaşılan problemlerin çözümünde iyi bir araç olarak kullanılabileceği gösterilmiştir. Bununla birlikte, yapılan anket değerlendirmeleri sonucunda, ankete katılan uzmanların ortak paydada da buluşamadığı ortaya çıkmıştır. Bu sebeple böyle bir sistemin geliştirilmesi hatalara objektif bir çözüm sunabilmesi açısından önemlidir. Ayrıca sistem, bu alanda yeni çalışmaya başlayanlar için iyi bir başvuru kaynağı ve eğitim aracı olarak da kullanılabilmektedir. Bundan sonraki aşamalarda, sistemin gerçek üretim hatalarıyla denemeleri yapılarak, uzman kişilerin hatayı çözerken ortaya koydukları yaklaşımla karşılaştırılmasının yapılması gerekmektedir. Bu şekilde, üretim esnasında daha efektif kullanılabilen bir başvuru kaynağı olarak da kullanılabilecektir.In this study, it is aimed to develop an expert system for troubleshooting of faults encountered in ink jet printing of cotton substrates. The possible faults may be observed during ink jet printing, prior to printing, such as fabric production or preparation, and after printing, such as fixation. Hence, at the analysis and selection of the most encountered faults in ink jet printing, the processes, which start with cotton production and end at fixation, are examined. After the detailed review of the literature and interviews with the experts, thirteen symptoms are selected as the most encountered problems in ink jet printing of cotton substrates. In addition, sixty-one causes are suggested as the possible causes of thirteen symptoms. Fifteen experts are asked to match each symptoms with sixty-one causes by using a five point likert scale, including most likely, likely, not sure, least likely and not related. In addition, the knowledge acquired from the survey and literature is embodied to the system. A different approach is adopted for the inference of the system in order to solve the problems that are selected by the users of software. The system demonstrates a good performance with embodied inference engine, which starts to solve problem from the common cause in the case of multiple selection of the faults. Moreover, the system shows that, it can be used as a tool for troubleshooting of ink jet printing of the cotton substrates. In addition, it is also possible to use the system as a training tool for the people who are new at ink jet printing.DoktoraPh