Final GC 440
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This 26 page Study Guide was uploaded by Allie S on Saturday December 5, 2015. The Study Guide belongs to GC440 at Clemson University taught by Dr. Weisenmiller in Summer 2015. Since its upload, it has received 194 views. For similar materials see Commercial Printing in Graphic Communications at Clemson University.
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Date Created: 12/05/15
GC 440 Final Exam Study Guide • Your goals: recall them from the beginning of the semester. Did you achieve them? o No thanks • Define “Commercial Printing”? o A means of communicating message that calls consumers to action (buying, persuasion, information, etc.) through the right means at the right time. • What is the largest printing company in America? o RR Donnelley • Name at least two reputable websites/publicatio ns that track the commercial printing industry. • GC’s mission statement: o To develop dedicated, practical, problem solving people for the printing, publishing, imaging, packaging, and allied industries. • Your problem solving process. o How did you implement a problem solving strategy during the past semester? Think about specific problems that you had with prepress, press, bindery, time-management, equipment, etc. • What steps can be taken by the prepress worker and/or the press operator to ensure consistency and quality from sheet -to-sheet and from job-to-job? o Proper maintanence, good make -ready • SOP’s (Standard Operating Procedures) – importance, level of detail, your SOP’s are derived from your notes taken during all of your demos in prepress, press, postpress. • Review the questions that you answered for the tour of Heidelberg. • Be able to differentiate the various printing processes addressed in Commercial Printing by their inherent characteristics, process variables, and products. 1) Principles of Design • Read the documents: “Basic Principles of Layout” & “Sappi Guide to Designing for Print” found on BB • Techniques for creating Contrast, Rhythm, Proportion, Unity, and Balance o Contrast – provides emphasis and catches the eye; works with rhythm to direct the movement of the eye o Rhythm – directs the eye; leads the eye in a direction toward the thing you want to see next; controlled by using contrast and balance § Techniques: patterns, shapes, colors, words o Balance – the even distribution of visual elements to create a pleasing effect; if a design is in balance, the elements seem to be equalized § Techniques: Informal, formal Informal – Asymmetrical, but typically more conceptual balance Formal – Symmetrical o Unity – inclusion or placement of elements so that they don’t clash with one another or the overall theme, tone, or message Techniques: All visual elements need to support each other and fit the overall Tone, Theme, or message o Proportion – appropriate size relationships among design elements • Typographic Design (Know the handout) and typographic points covered in lecture/lab including: o What is the difference between a “font” and a typeface”? § Typeface – Helvetica (no specific size); Font – typeface and a specific size and style Typeface – the “type” used; the physical type Font – the STYLE of the typeface; bold, italic, regular, semi Ex: Goudy Old Style Itallic 12pt Typeface: Goudy Old Style Font: Italic 12 pt (the specifics) o Identify Common Design Mistakes § Using bad artwork, poor t ypography, poor space awareness, underlining, all CAPS, too bold, widows/orphans § 3 rules of Graphics: Rule 1 Deliver the message Rule 2 Do NOT let the design Obscure the message Rule 3 Don’t use COMIC SANS o How is the choice of a typeface important? (See Helvetica) § Typeface is important because it can convey a brand’s mood, aesthetic, gender, demographic targeting o Know the Typography Handout: " A Basic Understanding of Typography” 2) Color Theory GGPP, pp. 53-67; (pp. 69-77, 2nd.Ed); Clemson University Brand Concept • Additive and subtractive color theory and their interaction with one another (very important) o R+G+B = WHITE LIGHT o C+M+Y = BLACK/BROWN Additive Color System · Tv, computer monitor · R G B · Equal amounts produce white · Start with black/nothingness – “add” color channels · Red + Blue = Magenta Red + Green = Yellow Blue+ Green = Cyan Subtractive Color System · Printing, inks, filters · C M Y K · Equal parts produce Black Cyan, Magenta, and Yellow to Subtract one of the Additive colors. These inks are just chemical filters that absorb different wavelengths. · Cyan + Yellow = Green Cyan + Magenta = Blue Magenta + Yellow = Red “I drink my RC cola down BY the river in my GM truck.” • Ink as filters: how they work o Printers use Cyan, Magenta, and Yellow to subtract one of the Additive colors. These inks are just chemical filters that absorb different wavelengths • Additive and subtractive mixing colors In THEORY, mixing CMY should make BLACK… However, in printing, usually creates a dark BROWN Need a neutral gray balance that is hard to achieve o Pigments are not pure o Paper is not truly white • Color perception: Factors that affect color perception, Effect of surround of color spaces: RGB, CMYK, Lab, HSL RGB and CMYK are device DEPENDENT Lab is device INDEPENDENT Retinal Fatigue – staring at certain image for too long, lens focus and become fatigued; changing your perception of color *Metamerism - appears to be the same under one light, but is different under another • Dimensions of common color Models o Numerical specification of Lab, HSL, CMYK, RGB § Clemson Orange § Clemson Purple o How Photoshop specifies color numerically (know the digital ranges of above color models listed above) Theoretical Grays: • RGB 127/127/127 • CMYK 50/50/50/0 • LAB 50/0/0 Actual Grays: CMYK 50/40/40/10 o How Clemson University specifies color: § Pantone - CMYK, HTML, RGB § CMYK – 0, 72, 100, 3; RGB – 234, 106, 32; HEX - EA56A20; Don’t do LAB anymore (Clemson Orange) • How is color difference expressed numerically? o Delta E is a measurement that numerically shows the difference between two colors. § Typically the human eye cannot visually discern a difference between colors within a DE of 2. • Explain why color differences occur between different output media. o Calibration of monitors, printers, and other equipment will lead the these differences o RGB space is LARGER than CMYK § The computer has a larger range of gamut than printer • Be able to draw a spectral reflectance graph of the primary colors. Red 600 - 700 Blue 400 - 500nm Green 500 - 600 (BGR) Cyan Magenta Yellow • How does absorption and reflection of primary colors of light/ink work? Be a ble to diagram this. 4) Digital Images & Photoshop Techniques for Print (GGPP, Chapter 4) • Software—types of applications and their purposes; what’s the correct tool for the job? o Photoshop is used for image effects and resizing; Indesign is used to make layouts; Illustrator is used for raster/vector design • Raster vs. Vector Image o Raster- resolution dependent = lose quality as you increase the size of the image o Vector- resolution independent = don’t lose quality as you increase the size • Special Effects - techniques and reasons for usage • Duotones (types, curves, purpose, and terminology) o Duotones only have one set of highlight dots; The curves in a subtle duotone have the color start at 30%; The curves in a color duotone have the black color start at 30% § Subtle: • Black curve is full power • Color curve starts at 30% (curved) § Color: • Black curve starts at 30% (curved) • Color curve is full power • Double-Dot halftone: what is it? How is it produced? What would the curves look like? o Double dot halftones have gre ater tonal range than a conventional halftone; The curves in a double dot duotone would be similar to those of a subtle duotone • Ghost halftone: maximum shadow values, tone curve o Normal halftone whose density has been reduced to a maximum of 35% to produces a very faint image; often used when you want to overlay text; You create a ghost halftone by adjustments > curves > drag shadows down to -35% · 5) Image Editing; What to know about Photoshop? (GGPP, Chapter 5) • Considerations of digital images. What to look for. o Type of original o Quality of capture/file o Resolution o Image adjustments o Output considerations o Feedback critique • Layer masks (Black, white, a nd gray areas of a mask: what do they represent?) o Back conceals, white reveals, grey is semi -transparent part of image • Layer adjustments, destructive or non -destructive? o Non-destructive § SEPARATE layers that allow you to make adjustments from. Does NOT delete any info o Channels § Can be RGB or CMYK -whichever mode your image is in -colors can be turned on and off from view o Info Palette – What can it tell you? § color values, width, height, and the XY coordinates of where your mouse is o Curves: input values/intensit ies vs. output values/intensities § Be able to draw curves that would generate: subtle and colorful duotones, ghost (halftone) images, high -contrast tonality in an image, shadow-/highlight-oriented images (high -/low-key detail) • High Key curve- steepen the highlight curve (towards the left) and you lose the shadows • Low Key Curve- steepen the shadow to lose detail in the highlight • Input intensity is on the X axis and matches up linearly to the output intensity on the Y axis o Histogram – What does it tell you? It indicates the range of tones that you’ve captured, indicated and over, under, or compressed capture. o Be able to list and describe the tools that allow us to evaluate image quality. o Vignette – How to execute with a layer ma sk, what is important? What can go wrong? o Converting to grayscale: what is important, 5 ways to convert § Adjustments>B&W § Adjustments>Saturation=0 § Adjustments>Desaturate § Adjustments>Channel Mixer § Mode>Grayscale o Converting to process color (CMYK): how and why use a profile? What profile is most appropriate for sheetfed offset? Heatset web offset? § GRACoL 2006 § o Extracting an image using selections/masks Tracing desired image and then using layer masks to reveal/conceal o Composite images: use of blending modes, layers, opacity, adjustments, and masks, unsharp mask § Layer the two images and lower the opacity of both to 31% to blend but you can use the blending modes that work better (darken, overlay, soft mix) · 6) Digital Halftones GGPP, pp. 250-263 (pp. 286-297, 2 .Ed); nd • What is the difference between “continuous tone” and a “halftone”? o Continuous tone images have an infinite number of colors, halftones are limited to one color, CMYK and use dots to trick the eye. Be a ware of moire (105,90,75,45) • Why do we print using dots? o Press limitations- a press can only print one density of ink o Simulation of densities of the original is the “best” you can do § Modulation- spots or dots, screening § Deception, viewing distance • “What is a Process Color Separation”? o Media that is printed using the 4 color CMYK o • What is the appropriate procedure for converting an RGB image to CMYK? What should you consider? o The loss of color when switching from a larger gamut to a smaller should be considered • Why/how do printer’s use dots to render photographs using the offset lithographic printing process? o The press limits us to one ink so we try to deceive the eye and use dots Due to Press Limitations · Presses can only run ONE density of ink · We are SIMULATING, using halftones to create highlights and shadows due to press limitations. On a press, there is only ONE density, therefore we need to use halftones to trick the eye into seeing highlights. • Name two ways to reproduce gray tones? o Grayscale o Channel Mixer>B&W • Basic densitometry: what does a densitometer indicate to a press operator? o Gives the press operator more control of the color throughout the press run, it can measure ink film thickness, dot size, registration and ink trapping • Grayscale & density (If a grayscale were printed with a 1.6 solid ink density, what percentage tint would produce a .30 density reading?) • Dot shapes and frequency (lpi): conventional (AM), stochastic (FM), and hybrid (XM); advantages/disadvantages of each o Stochastic (FM)- scattered randomly § Advantages- eliminates moire, eliminates tonal jumps, and you can scan in images at lower resolutions and they still print with same detail as a higher resolution scan § Disadvantages- graininess in shadows, expect twice the dot gain, more difficult to control on press (small dots wear off of the plate, more difficult to adj ust density on press for color correction) o Conventional (AM)- in an orderly and linear form o Hybrid (XM)- a combination of conventional and stochastic (GC Agfa RIP). Stochastic eliminates MOIRE, rosette, and tonal jumps; You can print at low resolution with no change. Disadvantages of stochastic is that there is graininess in shadows and specs in the highlights, twice the dot gain, and more difficult to control on press. • What is dot gain? TVI? o Dot Gain- halftone dots print larger than intended; mechanical and optical o TVI (Total Value Increase) - the reflection halftone percentage measured on a printed sample minus the original halftone percentage file value that produced it • How are digital halftones rendered? • Determining gray levels at a specific resolu tion/LPI • Causes of Moiré o Wrong angles, different LPI, Interference patterns encountered in scanning or exposing a digital photo 7) Prepress Layout & Preflighting (Chapter 6) The book addresses many of the concerns of layout (bleed allowance, font inclusion, avoiding crossovers, avoiding small reverse text, etc.) and digital imaging (maximization, resolution, cropping, etc.) and many more points that you should have become very familiar with in preparing and preflighting your booklet & brochure files for their print output conditions. In general, know what is important about creating a responsible file. Therefore, for the exam I would expect you to be able to do the following: • Using a Digital Imaging Checklist (What to look for when evaluating an image for reproduction) • What characteristics make an image suitable for graphic production on an offset press? Good and bad. • Know the appropriate software applications for specific lay out, workflow, illustration, and imaging functions. • Know how to install, embed fonts • Distinguish between Destructive vs. Non -destructive image editing • Know what tools can be used to preflight files • How can preflighting process be automated? • Describe ways that we can manually preflight files? • Why are some preflight points designed to indicate “risky design choices”? • What are the limitations of the preflighting tools that we’ve used? • What else would you add to a preflighitng list? • Margins, bleeds, column guides, grids: what are they, what purpose do they serve? • Risky Design Choices • What is important to look for when creating text wrap? o Know the risks involved with bleed allowance, transparencies, crossovers, reverses, large solids, gamut o Paragraph styles; what purpose do they serve? o Why is a “crossover” a risky design choice? Why is a “critical fold” (on a brochure, for example) a risky design choice? Offset Press Feeder, Registration, & Delivery Systems nd GGPP, pp. 303-318 (pp.338-354 2 Ed.) • Describe the basic concept of lithography o Image Carrier: a design is drawn with greasy crayon or ink on a flat limestone slab, to which the crayon adheres o Dampening: the stone is then moistened with water which is absorbed by the parts of the stone not covered by grease o Inking: using a roller, greasy ink is ap plied to the stone - the ink adheres only to the drawing and is repelled by the wet parts of the stone o Impression: a print is made by pressing paper against the inked stone drawing o Drying: the paper and ink are allowed to dry • Compare and contrast Offset Li thography with Digital Print Systems in terms of quality, value, and productivity • Digital: o Is best suited for runs of less than 1,000 o Leverages the power of Variable Data (VDP) o Better quality • Offset Litho: o Has a higher set-up cost o Price per piece diminishe s with quantity st o 1 hour of make ready is about $500 but once you get going the price goes down and you save money • Compare and contrast Offset Lithography with the basic process of Flexography o Costs more: higher setup, press costs o More complex: longer, more involved setup o Not as versatile in range of substrates o Uses a planographric image carrier • List and describe technological trends in press technology o Integrated computer workflow § Hybrid capabilities § Mixing processes: digital, flex o, rotary screen, etc. o Increased inking capability § Auto ink dispensing and ink zoning § Larger form rollers • Prevent ghosting and roller starvation • Anilox fountain roller (engraved) o Improved automation and controls § Cleaning, loading, temperature controls § Closed-loop color control o UV technology • Name and briefly describe three North American Print conditions. o GRACoL #1- General Requirements for Applications in Commercial Offset Lithography o SWOP #3- Specifications for Web Offset Publications o SWOP #5- Specifications for Web Offset Publications • Understand the aspects of print quality including: density, trap. • Describe the sheet feeding and registration system in terms of standard operating procedures and press mechanisms. • Explain the importance of the “register corner”. o It is the straightest corner and it helps you properly align the sheet with respect to the image on the blanket Offset Printing Unit Mechanics, Ink & Chemistry Handbook of Print Media, pp. 206 -260 Ingredients of lithographic ink Colorant Pigments can be organic or inorganic Vehicle Vegetable oil base (Linseed oil) Resin (Natural or hydrocarbon) Additives Waxes, driers, etc. Drying agents (catalysts) Cobalt – top dryer Manganese – through dryer Heatset Web Offset Inks Mineral oils used in vehicle, evaporated off in heat dryer Ink drying: how do common offset lithographic inks dry? Distinguish between “setting” and “drying” of inks. Setting—30 min. to two hours; the top of the ink film dries enough to print again To determine if ink has set, try to smear the ink with your finger and a light touch Drying—about 48 hours Oil-based Dries primarily by evaporation and oxidation, will form an ink skin in the can (additives) Rubber Based Dries by absorption (no skin) UV Photoinitiators Cured by UV light and dries instantly · Tack: sequence, interact ion with substrate, wet trap. What problems can occur if ink is incorrectly sequenced? • KCMY...K is the tackiest...Y is the least tacky • The tack is more important than the ink order • If you do it wrong you can have ink migration - it pulls the previously laid down color back onto the blanket and off of the substrate. Then it transfers to the blanket and can affect the ink plates. Ink contamination. · List the main functions of the inking system of an offset lithographic press • Works the ink from plastic stat e to the semi-liquid state • Distributes a small thick film to an even, thin film all around the form rollers (.05 mils) o Deposits a uniformly even, think film of ink on the image o Picks up fountain solution from the plate, emulsifies partially into the in k, evaporates the rest o Picks up foreign matter and holds in suspension until the system is cleaned · Explain how is “impression” and “squeeze” adjusted between cylinders. · Be able to label a diagram of our Ryobi 3305HA press. · Describe and diagram an Anicolor inking system · Explain how ink level is controlled on a litho press. • You can tighten the ink fountain keys which changes the amount of ink transferred to the fountain roller • Or adjust the dwell - how long the first doctor roller contacts the fountain roller · What is the composition of fountain solution? How is it measured and controlled. Imposition: • Refers to the position of pages on a press sheet so that, when fol ded, the pages are in correct order and right side up. • Explain the considerations of creating an imposition. o Design of the piece to be printed o Size of the printing press o Type of paper being printed o Bleeds • Define Work and Turn/Tumble & Sheetwise impositions o Work and Turn - both sides of the paper are printed on the same. One side is printed then the page is flipped sideways and prints again to make two identical booklets. (ex: print 1-8 on one side, 1-8 on the other side and cut in half vertically to make 2 b ooklets) o Work and Tumble - both sides of the paper are printed on the same. One side is printed then the page is flipped head over tail to make two identical booklets. (ex: print 1 -8 on one side, 1-8 on the other side and cut in half horizontally to make 2 booklets) o Sheetwise- each side of the paper is printed differently. (ex: print 4 copies of the front on one side of the page and when it dries flip it over and print 4 of the back to make 4 brochures) • Why would an imposition include a “Binder’s lip” o If it did not you would not have enough room to bind it once it was trimmed and you would cut into the image area • Know the terms: “head”, “foot”, & “face”. o Head is towards the fold (top of page) o Tail is away from the fold along the bottom (bottom of page) o Face- • How do you spec a 4 -page folder? Digital Offset Printing • Differentiate electrophotographic printing from/offset/high -speed ink jet/heatset web offset • The Indigo printing cycle (Reference pp. 6 -7 in the document “HP Indigo Digital Offset Color Technology ” found on Blackboard.) • What products may be printed digitally? Photo books Booklets (signature, squarefold and lay flat options) Brochures Posters Postcards Business cards Manuals Calendars Newsletters Trifold fliers Invitations • Review the video demo nstrations at: • https://www.youtube.com/watch?v=vl9 -Jj4n858 • https://www.youtube.com/watch?v=TdWYXhG0rJ4 High-speed (wide format) Ink Jet Printing • Webfed HP T400 - Review the video demonstrations at: http://www.youtube.com/watch?v=AjIDOtRmf4A DI Technology • What does ‘DI’ stand for? Digital Imaging • Describe the plate material and the imaging process for a DI plate making system. • Describe the advantages and disadvantages of waterless ink. Advantages of Waterless Printing -reduced waste -shorter makeready -better ink holdout -better image detail -better consistency • Explain the concept and review the demonstration video at Presstek.com • How does it compare to digital printing and conventional offset? • Although the DI is not a ‘digital press’ per se (it is a hybrid press), what is the ideal run length of a true ‘digital press’? Sweet Spot” = 500-5,000 • Plate material o Water offset plate with digital imaging by thermal ablation o ProFire Excel laser strikes plate o Top oleophobic silicone layer repels ink from non -image forming area o Beneath the silicone is an imag e forming titanium dioxide layers o Base layer of polyester provides stability and serves as ink receptive layer o Offset inks adhere to the oleophilic (ink receptive) layer, in areas revealed during imaging • Waterless lithography advantages and disadvantages § Advantages § Higher line screens 300 -800lpi for better image detail (sharper dots) § Better consistency thru runs § Higher tack inks, faster drying times § Higher densities, better ink holdout, greater tonal range § Makeready cut in half § Elimination of ink and water balance variables yields reduced running time and waste § Better register control § Elimination of paper stretch caused by fountain solution § Elimination of hazardous VOCs and wastewater • What a typical run length for a DI press? H ow does that compare to digital printing and conventional offset? DI Press = 500-5,000 Digital =best suited for short runs (1,000 or less) Offset = best for LONG runs HP Indigo Technology & Electrophotography • HP Indigo: identify and describe the purpose of the main press components on a diagram of the Indigo 5000. • Read the white paper document (on BB): “HP Indigo Digital Offset Color Technology” • Explain how the print engine on an Indigo works. o How is an image generated? o How is an image developed? o How is an image transferred to a substrate? • What controls/monitors density of the electroink on an Indigo? • Why would you use one shot vs. multiple pass printing? • What are the ingredients of elect roink? -ink pigments -imaging oil -imaging agent • In which order are electro-inks printed? Is this sequence able to be changed? YMCK - but it CAN be changed (remember that Litho is KCMY) • What is the format (size) of the HP Indigo 5000, HP Indigo 10000? HP Indigo 10,000 · 29-inch format (B2- back to paper) · 3450 sheets per hour (4/0) 4 colors on one side, 0 on the other · Up to 7 colors HP Indigo 5,000 (GODFREY) · 12 x 18 Format (2-up) · · Up to 7 colors • Be able to discuss basic print quality troubleshooting. Augmented Reality • What is Augmented Reality? o Mixing virtual objects with the view of the real world • Name two AR applications. o Aurasma o Layar • Explain how an AR System works? -smartphone, tablet, or computer camera needed -app needed - download from App store -trigger needed - this is what causes the AR to happen (designed using the app software) -triggers need to be thought out and tested • What are the components of an Augmented reality system? Trigger - an image that when used by the AR App, triggers an overlay Overlays - any imagery that is triggered when using an AR app User App Phone • Where can we see AR in commercial/marketing applications? Be able to describe an example of AR. • Explain how AR is used in tandem with print media. Provide an example. AR is a way of creating a user-interactive marketing. Ex: Ikea - letting prospective customers “try out” the furniture • Compare and contrast the advantages of AR to its barriers/limitations of proliferation? E.g.: Pro’s and Con’s of AR. PROS: -ease of use -practicality -measure of success -cost -possibilities CONS: - Need a SPECIFIC AR app to read, not universal Practical Points of Paper GGPP, Chapter 08 • Paper Math o (L x W x Basis Weight) / (X sq. in basic sheet size) • Caliper: How is it measured? How is it expressed numerically/verbally? o Paper thickness § Measured with a caliper in thousandths of an inch • Basis Weight: Be able to define it. How is it used practically in paper selection? o A standard set for referring to the different papers w/ a classification o The weight of 500 sheets of the basic size sheet for that class of paper o g/m = the metric equivalent of the basis weight, not dependent on standard sheet • Basic Sizes: Memorize the basic sheet sizes for: o Bond: 17 x 22 o Text: 25 x 38 o Cover: 20 x 26 o Index: 25.5 x 30.5 • Be able to draw out (diagram) a basic cutting plan (similar to the one that you used in lab for your press test). Press testing & Process Control GGPP, pp. 364 -374 • Why do we press test? How often? o Calibrate press performance within a specific workflow to determine and adjust the quality parameters expected for a press and materials used . • Materials Specification: paper, ink • Appropriate line screen frequency • Solid ink density (SID) – How do we determine? • What is G7? o An ICC profile that helps with CMYK • GRACoL specifications of materials, process variables. Be familiar with the GRACoL specifications. Not the exact numbers, but the concepts. o General Requirements for Applications of Commercial Offset Litho • Print contrast – What is it? Why and how it is co mputed? How is it used to optimize a print density. • Total Area Coverage (TAC) o What is the highest TAC for a grade 1 sheet for offset (for example)? • Dot gain (TVI) compensation curve o Mechanical vs. Optical dot gain o Tone Value Increase- The reflection halftone percentage measured on a printed sample minus the original halftone percentage file value that produced it • What two ways can a “Goal Density” be determined? 1. one way is to look up the STANDARDS TABLE and fig ure it out based on process/paper in order to determine what your GOAL density is – using the table below specifications 2. Press test (if substrate not on the chart) · (Density of solid – Density t)/ Density of solid X 100% = % • As halftone screen frequency (LPI) increases, what happens to dot gain (TVI) values? o IF LPI increases, so does dot gain (Direct relationship) • What are the reasons for mechanical dot gain? (Think about the variables from job to job and within the printing process.) o Ink film thickness o Substrate characteristics o Impression o Running speed of the press o Plate exposure o Ink rheology o Mechanical - occurs as a result of platemaking or press operations that cause the geometry of the dot to change. o Optical - occurs when light is trapped under dots and thus the dots appear optically larger (illusion) o Recognizing there are constantly changing va riables in the printing process, what factors would cause the print contrast test to be run again? § Recalibrating press every month § Temperature/environment changes § Process control – same process every time – therefore any change requires a calibration § Lack of maintenance § Slur – want a kiss impression § Ink pigment settlings § Improper make readies • Recognizing there are constantly changing variables in the printing process, what factors would cause the print contrast test to be run again? • What factors would impact the optical dot gain the most? • What is the purpose of and what are the *limitations of using densitometers to evaluate the press sheet, as was used in our class (be careful you list the limitation of the densitometer and not the limitation of the process created by an experienced user - e.g. it needs to be calibrated, this is no problem for experienced operators, they do it in 30 seconds)? Press troubleshooting GGPP, pp. 329 -339 • Common offset press problems: their common causes and soluti ons • Name five issues contributing to (slow) makeready time. • Know the major cause -and-effect relationships of print problems covered on this upcoming Monday’s “You Gotta Problem” presentation. Completing the SHOTs simulator exercise prior to the exam is als o advisable. • (For example: Symptoms and causes of slur, and other print quality defects) • Causes/issues related to the following print defects/conditions: o Hickey o Scumming o Dimensional Stability (of substrate) o Picking o Blinding o Over-dampening- causes the image to blur and the ink to fade o Contaminated ink in second printing unit - If ink is not in the correct sequence, then this can cause the least tackiest ink to pull off the impression cylinder (with substrate) and back onto the blanket. o Dot gain- o Mechanical Ghosting o Set-Off o SID is laterally inconsistent Finishing, Binding (Be familiar with Chapter 10) • The difference between a knife folder and a buckle folder o Buckle folder hits the buckle and pushes down to hit another buckle (our folder) o Knife pushes down in the middle of the papers • What is the purpose of a binder’s lip? • What is important to know about postpress operations during the design phase? • What is the cover of a hardbound book called (in terms used in the bindery)? • How can Value-Added be pumped into a product in post -press? • Differentiate a flying splice from a zero -speed splice.
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