Welcome to GRPH 390: Production Graphics
These pages are provided as an outline for GRPH: 390 Production Graphics. At right you will find links to the material covered each week throughout the course, as well as links to each assignment, distributed via Adobe PDF files. Though this site is updated frequently, all materials and assignments are subject to change at Instructor’s discretion.
Things to know, remember, and understand.
This material is a supplement to class and does not replace class attendance and participation. For more information regard attendance policies, please refer to the Marietta Student Handbook.Assignments for class will be assigned in accordance with covered material. PDFs outlining each assignment will be made available on this site (at right) throughout the semester.
Materials & Text(s)
See Syllabus for complete details.Syllabus_390_spring08.pdf
Text Books: Required Reading From….
• A Guide to Graphic Print Production• Getting it Right in Print Digital Prepress for Graphic Designers
These texts are comprehensive guides to the print production industry and although you are not required to purchase either of them for this class they can be purchased on line via third party vendors such as Amazon.com.
if you wish to add them to your personal collection of references.
Other Noteworthy References: NOT Required.
• AGetting it Printed How to Work With Printers…• Forms Folds and Sizes
• Real World Print Production
• The Official Adobe Print Publishing Guide
Additional information on many of the topics we will cover in class can be found in these books, but they ARE NOT required for class at this time.
$25 lab fee: Required.
This fee is to offset the cost of printing paper and ink used in the computer lab for class assignments.$50 print production expense: Required.
You will be required to work through a local print vendor(s) to complete one of your assignments. This fee will help to fund your pre-press and printing costs.I will collect all fees at the second class meeting. (Wednesday. Jan 23). Make 2 checks (one fore each fee) payable to the Marietta College Art Department. If you fail to pay your lab fee, your grade for the course will be withheld until it is paid in full.
Epson Ink Cartridges: IF Required…
Students will be responsible for buying their own ink. Ink needs to be brought to class when needed. Students are responsible for loading and unloading their own ink from the printers. It is recommended that students store and carry their ink cartridges in an index card box.
Other Places to Buy Epson 1280 Ink
Information about Epson 1280 Printers
Epson Paper: IF Required…
The Classroom printers need compatibale paper to reneder the best quality projects. Students can purchase these papers locally at Parkersburg Office Supply by calling 1-800-525-1951 24 hours in advance and ordering over the telephone. Orders are shipped to the store in a day.Reading Assignment (PREP)
• TEXT: A Guide to Graphic Print Production: Chapter 1: pgs 9-32 up to sec. 1.6Graphic Print Production
Graphic Print Production can be defined as “All the steps that are taken to produce a printed product.”Factors to Be Aware of:
• There are multiple roles / people
• Success is partnership dependent
• Costs can be unpredictable
• Proper planning and knowing what to ask pays off
A word about “The Graphic Print Production Flow”
Today, thanks to technology, one person can and is often expected to do more different jobs whereas, in the past it used to take more people, each specialized in particular parts or areas of the production process.So who does what? And what’s the process?
There are 8 basic Steps to Graphic Print Production…
… and together these make up 4 Phases
A. Idea and Concept
1. Strategic work ( the thinking part )
2. Creative work ( that would be us )
B. Creative Production
3. Image and text ( the grunt work )
4. Layout ( the fun part )
C. Industrial Production
5. Prepress ( the last chance to make big changes)
6. Printing ( the loss of control )
7. Finishing and Binding ( putting all the pieces together )
D. Logistics
8. Distribution ( getting the project to the end client )
Idea and Concept: Strategic Work
Who does the Thinking?What do they ask or figure out?
What are the goals for the project?
Who is the audience?
What will it be used for?
Idea and Concept: Creative Work
Developing the design. Determining the message. Figuring out how to best communicate with the audience.What type of printed product should be crated?
What should this product say?
How should it say it?
What will it look like?
Creative Production: Images and Text
Thanks to digital devices, and technology advances now everyone’s an expert. Right?• issues with image quality
• issues with size
• issues with cropping or edited info
• issues with archiving / organization
Image editing consists of both checking for technical quality and achieving creative goals. There are basically two types of images that we will work with:
1. Pixel based images
2. Object graphics
Creative Production: Layout
The preparation of the layout for printed products extends beyond making it visually appealing.Elements within layout consist of:
• typography
• manuscript / content
• image use (selection and editing)
• color choice and use
• knowledge of the printing process
Industrial Production: Prepress
So what is prepress exactly? The steps and techniques required to create print-adjusted digital files that can be the foundation for the production of printing.• creating PDFs
• print adjustments of images
• proofing
• imposition
• rasterizing
Industrial Production: Printing
There are various types of printing methods. They are typically determined by:• quality requirements
• edition size
• printing material and format
• type of finished product
There are basically two types of printing:
1. Printing press technique
2. Printer technique
And then there’s digital printing which is based on the “printer” technique but is capable of competing with the traditional expectations of an off-set press.
Industrial Production: Finishing and Binding
This should be considered from the beginning of the process because what you want to produce and how you intend for it to be handled by the user is directly impacted by the binding and or finishing process.Basically Finishing & Bindery has 3 areas
1. surface processing
2. off press processing
3. binding
How / Where / or Who takes care of the Finishing or Bindery work will vary depending on its complexity.
Logistics: Distribution
The final step, is otherwise identified as how the product gets where it’s going to be (i.e. mailing or shipping) often can be more expensive than printing itself. This is frequently a service provided by a third-party vendor.Reading Assignment
• TEXT: A Guide to Graphic Print Production: pgs 18-36Before Production
Before you begin any work some consideration should be given to the following:1. Why are you making it? (what is it’s purpose)
2. Who should it reach?
3. How should they be reached?
4. What kind of printed product should this be?
5. What are the quality demands?
In thinking about these different factors and how they interrelate you will make some key decisions about your work or project that will directly affect or impact the decisions you make in the production process. In answering these questions you will be organize and formulate your process for acquiring or obtaining job costs.
1. Why are you making it? (what is it’s purpose)
The answer(s) to this question should begin to lead you into what format you need to be considering for the project. And in large part it’s the format that will set the stage for the project planning and job costing. For example:
• If you want to persuade someone to buy something,You make an advertisement.
• If you want to impart information,You make a newsletter
• If you want to entertain or educate,You make a book
• If you want to package something, You create packaging
2. Who should it reach? & How should they be reached?
Your target audience will help you formulate some layout decisions with regard for type and graphic / visual style. Determining your “target” audience will also lead you to consider media or how best to reach your audience.
Some examples of “target audience types”
• Youth
• Retired people
• Median Income
• Food lovers
Some examples of “media”
• Large advertisements around town
• Ads in the newspaper or magazines
• Direct mail
4. What kind of printed product should this be?
The type of printed product will be set by the audience type and the media combined. For example if you were doing a direct mail project you would be most likely completing a postcard or flyer and NOT a poster. And if you are doing a direct mail project for a select audience (i.e. 55 plus members of a small community) the distribution would be small enough that a self mailing brochure becomes a viable option.
On the other hand if you were doing a 50,000 plus general coupon mailing to a less specific audience, it may be more cost effective to produce a simple 2-sided postcard.
5. What are the quality demands?
Knowing how the product will be used will help to determine the quality standard for which you should work toward. Keep in mind that the demands put on quality will directly affect your costs. Typically the better or higher the quality, the higher the cost. In considering quality, it is best to calculate the relationship between the end user or “target audience” and how the piece will be produced. Some questions to help formulate your plan might be:
• should it last a long time
• should it be of archival quality
• will it be leafed through frequently
• is it going to be thrown away immediately
Production Costs
Now that you’ve considered1. Why are you making it? (what is it’s purpose)
2. Who should it reach?
3. How should they be reached?
4. What kind of printed product should this be?
5. What are the quality demands?
and likely come to some conclusion about what you are producing you will have some of the information required to do some comparison shopping.
So what affects or impacts the production costs?
There are many inter-related elements that can either increase or lower your printing costs. It is up to you to make informed decisions to manage your costs. There are some projects that will require an accounting and allowance for each of these factors, but some projects may only utilize a select few. (i.e. you may not always elect to include the archiving as part of your job costing.)
1. The “Makeready” or Setup Involved
2. Edition Size / Format / Volume
3. Color Use
4. Image Editing
5. Layout work
6. Prepress
7. Finishing / Binding
8. Paper
9. Packing and Distribution
10. Archiving
11. Environmental Concerns
Vendor Selection
Your vendors are your “friends”—and your relationship with them and how and when you utilize them will have a direct impact on your success as a designer. So choose them wisely and consider them as a partner in your production process. Respect their role, and be considerate of their work. Some Factors to Consider When Selecting a Vendor
• quality and competence
• delivery times / guarantees
• capacity and resources
• organization and working together
• proximity and availability
• references and direction
• routines and conditions
• quality and environmental work
• economy and future
Planning
Generally the planning comes after you’ve collected your offers on printing. This can be the most challenging part of the process due to the variables and the number of participants you must rely on to complete the project.As a general principle when it comes to planning production, one should “expect the unexpected” and plan accordingly.
Some things to consider and anticipate in planning:
• Who is in charge?
• Are you qualified to be in charge?
• Who should be included in the project?
• Who is responsible for what parts?
• Who should check proofs?
• Who will be giving the project final approval?
• What vendors are needed for the project?
• What will you be doing?
• What will your vendors be doing?
• Do you have these contacts already?
• Who should be keep informed of what and when?
• How will you guarantee quality and time frames?
In order to answer these questions and lead a project:
• you must understand the production process. There are 8 basic steps.
1. Strategic work
2. Creative work
3. Image and text
4. Layout
5. Prepress
6. Printing
7. Finishing and Binding
8. Distribution
• you should be aware of how each step impacts the next
• you should be able to assign reasonable time allowances for each step to take place
When planning
• start with the delivery date and work backwards
• be aware that changes in the early stages are notnearly as costly as those that take place later
• be sure to set check points
• allow for errors / build in some padding or at a minimum be aware of where some flextime can exist if needed.
Reading Assignment (PREP)
• TEXT: Getting it Right in Print; Chapter 1; pgs 7-18• TEXT: Getting it Right in Print; Chapter 4; pgs 31-36
The Changing Face of Graphic Design
For the most part the printing industry consists of two separate areas of expertise.• Those who run the presses (i.e. the printers)
• Those who supply the work (i.e. graphic designers)
Since the 1980’s the work of graphic designers has evolved from the mechanical assembly of the basic layout, into which the printers photographic department placed the relevant images, to the production of digital files that contain absolutely everything needed for the job.
Digitization has been a major development in the industry, yet while methods used to produce digital files continue to evolve at high speed, the designer and the printer have generally remained within their own traditionally defined areas of expertise.
The Result:Most of the printing process remains a mystery to the people who need to understand it the most—the designers.
Graphic Design: a two part industry made up of:
• designers
• printers
What we don’t know CAN hurt us
As designers a lack of understanding about the print production process and the methods used to produce printed material can leave us with very unsettled thoughts about the outcome of our work once it leaves our hands.Fear of an Unknown Outcome comes from:
• lack of understanding
• methods of production
• digital technology
Typical “Gray Areas” for Graphic Designers:
Being aware of and understanding these terms can help you to prepare work in a manner that could save you time and money on every job you prepare for press.
• image calibration
• dot gain
• RGB vs CMYK
• screen clash
• trapping
The PDF file (surfaced in the 2000s)
Initially thought of as a solution to the “gap” between designers and printers, this particular advance in technology, only seemed to cause more problems.
• negative for designers (leaving more responsibility to us)
• a positive for printers (no more messy files to manage)
From the beginning:
Letterpress Printing Technique(the act of inking letters and pressing to paper)
• wood
• movable type —clay type (China 1041) —metal type (Europe 1440)
• type used with illustration (1461)
• variable character styles (1476)
Photographic Process (came with the invention of photography 1830’s)
• introduction of the film based process
• brought about the new use of images
• created a desire to move away from wood cuts
• halftones evolved (1890)
The following illustrates the process of generating a halftone from a continuous tone image:
Halftones: used to create the illusion of gray
A. light reflected through the original image travels through a screen
B. this produces halftone dots of various sizes on a sheet of film
C. the image in film is transferred to a plate using a contact exposure
D. the plate is process and thus usable in print
Typographic Advances
• IBM Selectric
(typewriter / golf ball head)
• rub-down type
• phototypesetting machines
• CRT and HTML
• linotype
(came as a single character set NOT font family)
FYI: Something to consider, in the days of linotype and compugraphic phtotypesetters, a SINGLE font film strip cost around $165!
Computer Fonts
• bitmap fonts / type
(single fixed resolution; new type size meant new font file; i.e. NOT scalable
• postscript / type 1 fonts
(developed by adobe; vector based; consisted of two files– one for the screen image and one for the printer; these are NOT cross-platform)
• truetype fonts
(scaleable vector outlines; made from a single digital file — not two separate as with postscript; not truely as “clean” as postscript, but only noticeable at larger sizes)
• opentype fonts
(these ARE cross platform; use a single font file for all outline, metric and bitmap data)
Film technology and Lithographic Printing Technique
Two main elements:• film / film processor
• plates / plate processor
Based on the photographic process
• documents are printed to film using a film processor
• images are transfered to light sensitive plates using the photographic process
• plates are is processed and installed on the press
• exposed plates attract oil based substances and their backgrounds attract water
film stripping consists of:
• assembling film
• putting film to plate
• vacuum sealing
• exposing to light
Clearly this process can be extensive, time consuming and to say the least expensive when it comes to making changes.
Traditionally when films were more common, the most utilized process for checking proper separation was the blueline proof.
plates there are two types
• Negative Plates
(generally used in the US and can be preserved using gum arabic to de-sensitize to light)
•Positive Plates (European and NOT re-usable)
Filmless technology and Lithographic Printing Technique
available locally, at Richardson Printing Company Also known as Computer to Plate (CTP). With this technique there is:• no need for film
• no need for film stripper(s)
• no need for processing chemicals
the result:
• minimized time
• reduced dot gain
• near perfect registration
Filmless AND Plateless Printing Technique
available locally, at Premier Printing Also know as Direct Imaging (DI) With this process plates are imaged right on the press there is:• no film
• no film stripping
• no film processing / processor
• no plate processing
the result:
• faster turn around
• more affordable printing
Digital Printing Technique
available locally, at Hyde Brothers PrintingThis technology is similar that of a laser printer. The images are created electrostatically on a drum thus making them easily changeable. With this process:• there is toner / not ink
• there is no film
• there are no plates
the result:
• very affordable
• lower quality
• unique impressions
The Offset Litho Process
Offset lithography consists of these basic steps:1. paper is loaded onto the press
2. a series of suckers feed the press one sheet at a time
3. grippers grab and pull each sheet into and through the press
4. color is added one one ink unit at a time
5. the paper is released and stacked at the other end of the press
Different Projects / Different Presses
Presses vary in size and are often referred to by the number of inking units on them. (i.e. two color-, four color-, and six color-, units) Likewise, each type of press is ideally suited for particular jobs.• two color units (smaller runs / stationery / business cards)
• six color units (larger more complex pieces / brochures)
Below is an illustration borrowed from our text “Getting it Right in Print” showing the way the rollers / ink unit works on a offset litho printing press. For each color on the press there will be one of these units:
the ink
• at the top there is an ink trough
• in the ink trough there is a single roller that turns slightly ever few seconds
• behind it is another roller which jumps forward to touch it
• this second roller transfers a long bead of ink to a third roller
• the ink travels through a series of rollers / the inking system
• eventually the ink is delivered to the surface of the plate
the dampening system
• located behind the plate cylinder
• consists of a smaller cluster of rollers
• covers the background of the plate with pH balanced solution (mostly water)
the blanket cylinder(hence the word “offset”)
• located beneath the plate cylinder
• wrapped with a soft canvas backed sheet of rubber
• picks up the image from the plate
• and transfers it to the paper
the impression cylinder
• located beneath the blanket cylinder
• presses the paper against the blanket to pick up the ink
• the image is the result
the stop bar
• located at the other end of the press after the last unit
• catches the paper as it is released from the grippers
• the sheets are stacked and hit with set-off (cornstarch)
Web Offset Litho Printing
Basically the same as sheet-fed litho (described above), but on a much larger scale.• prints continuous roll of paper (hence the word “web”)
• capable of incredible speed
• prints both sides of the paper at once
• has an inline finishing unit (folding / cutting / binding)
• uses infra-red or propane dryers between each inking unit
exception: newsprint web press uses cold-set inks, made to dry quickly on super absorbent stock—like newsprint
• inks are thinner (resulting in increased dot-gain)
Flexography or Flexographic Printing
Mainly used for packaging. this technology is locally available at Premier Priniting Also often used for labels. Characteristics of this technology are:• plates are like a mold or stamp
• plates are able to give with the pressure applied (major dot gain)
• registration tends to be very loose
• capable of printing on non-absorbent surfaces
Screen Printing
Generally used in reproductions on cloth or clothing and physically large pages (as wide as 15 feet) on very small runs, this technique has the following characteristics:• a metal frame with fine polyester mesh make up the screen
• ink is poured into the frame and forced through the screen
• not ideal for fine detail printing
• both manual and machine operated
Gravure
Commonly this is used to make banknotes or documents subject to forgery.• plates are thicker than those used in offset
• plates are either diamond etched or laser etched
• the ink is thinner and is intended to fill the cells of the plate
• excess ink is continually wiped from the raised surface
• the result is a continuous tone
• not so good for type
• the very best for image reproduction
• extremely expensive production process
• suited best to extremely long press runs
Reading Assignment (PREP)
• TEXT: Getting it Right in Print; Chapter 2; pgs 19-24• TEXT: Getting it Right in Print; Chapter 4; pgs 31-36
• TEXT: Getting it Right in Print; Chapter 15; pgs 127-132
“K” is for Key Plate
Referred to as K in the scope of CMYK, the color black is considered to be the “key plate”. This is the plate that all of the other colors on the press are keyed to.• text
• image borders
• printed first in order
Screen Angles & Screen Clash
When printing in four color process or simply with more than one color there is potential for screen clash.• the scanner and computer capture the image
• the imagesetter rasterizes the image
• the result is pixel information / halftone
Line Screen
• printer terminology
• long lines of dots at 90 degrees to each other / halftone
• 150-dot halftone = 150 line screen
• different for different printer types / technology
• different for different paper(s)
Images of More than One Color
• line screens cannot be identical
• moire patterns / screen clash
30 degree rotation rule
• first color at 0 or 90 degrees
• second color turned 30 degrees
• third color turned another 30 degrees
The Fourth Color
So where do we put the fourth color if all our angles are already used?• cannot go another 30 degree turn
• placement is dependent on the nature of the colors
—black as darkest – yellow as lightest – cyan & magenta in the middle
• yellow is the variable
-moire not visible
-15 degree angle
-vertical / horizontal line
• detectable line angles
-90 degree most obvious (yellow)
-45 degree least detectable (black)
standard angle assignments are
• yellow at 0 or 90 degrees
• black at 45 degrees
• magenta and cyan 30 degrees either side of black
-at 15 degrees
-at 75 degrees
correct application of screens prevents visible moire or screen clash:
Beyond Four Colors
Some common printing techniques that reach beyond the standard practice of 4-color process are:• Stocastic / Frequency-modulated screens
• Hexachrome
• Pantone Matching System
Stocastic / Frequency Modulated Screens
halftones (different dot sizes / fixed grid system)stocastic (random dot pattern / varying densities)
• no grids / no screen clash / no moire
• no grids / no risk of moire = limitless colors
Problems / Disadvantages
• requires extremely small dots
• dots too large make image grainy
• dots to small can plug up on the press
Hexachrome and Stocastic Imaging
• six color imaging separations- CMYK – orange – green
• 600 dpi (dots per inch / NOT line screen)
Hexachrome and Screen Angles
• Orange and Green extend the range of color• Orange or Cyan (only one occupies the screen)
• Green or Magenta (only one occupies the screen)
Hexachrome and PMS matching
• over 90 % matchable using hexachrome• minimize / eliminate need to wash presses
• packaging industry leading customer use of this technology
Pantone Matching System
(PMS) and Spot Colors are often utilized for the purpose of achieving non-typical or specialized and higher quality results on the press.The characteristics of PMS colors are:
• custom mixable formulas
• mixing services / charges
• mixed colors made from the standards
-C M Y K – Yellow 012 – Orange 021 – Warm Red – Red 032 – Rubine Red – Rhod. Red – Purple – Violet – Blue 072 – Reflex Blue – Process Blue – Green
• no exact match for a spot color using process mix
• ideal for two-color work / duotones
Problem Areas Using Pantones
A)Clients use a particular pantone color for their logo, and now want a 4-color brochure / ad / newsletter but don’t want the added expens of running a 5th color so the pantone color will now be converted to CMYK, and of course will most likely not convert accurately.B)Client understands your problem with the pantone conversion to CMYK and opts for the 5th color. How do you show them an accurate proof.
• Solutions:
-cromalin proofs and dab tests – wet proofs
3)Client goes for the fifth color option on the print run and then wants to see their lovely logo overlap a CMYK image
• Solutions:
- If pantone is solid. – If pantone is a tint / screen
Other Pantone Products
Metalic Formula Guide:• 204 colors
• relies on hard / smooth / coated surface paper
• varnish use
• spot vs. flood
• before or after
Pastel Formula Guide:
• 126 colors
• minimize waste to custom mixing
Class Exercise: Adding logos or spot colors to image files: DCS2 files Color Separations
Reading Assignment (PREP)
• TEXT: Getting it Right in Print; Chapter 15; pgs 127-132
• TEXT: Getting it Right in Print; Chapter 11; pgs 91-102
• TEXT: A Guide to Graphic Print Production, pgs 101-121
Digital Images
There are two main types of digital images:• Object Graphics
• Pixel Graphics
Object Graphics consist of mathematically calculated curves and lines that create surfaces and shapes.
Pixel Graphics are images consisting of pixels of different colors, squared to picture elements.
Object Graphics
Object graphics can include simple curves, straight lines, circles, squares, typefaces and other graphic objects.Object vs. Vector Graphics
• Vector images are based on straight lines
• Object images are based on “bezier” curves
Bezier curves were named after a mathematician at the French car manufacturer, Renault.
Object Graphics are based on a number of basic components:
• Outlines and Lines
• Fill
• Patterns
• Gradients
• Knockouts
• Superimpositions & Transparency
Advantages and Disadvantages
+ contain an unlimited number of colors
+ Can be rescaled without compromising image quality
+ Easy to edit without compromising qualtiy
+ Don’t take up a lot of memory
– Cannot be used for photographic images
Applications for Object Graphics
Object graphics are created in illustration software:
• Illustrator
• Macromedia Freehand
• Flash
Pixel graphics can be converted to object graphics using:
• Adobe Streamline
• Freesoft Silhouette
File Formats for Object Graphics
Below are descriptions of the most common file formats used when saving Object graphics along with some advantages and disadvantages for consideration:+ Can be opened by everyone
+ Is the same for Mac and Windows
+ Files use little memory
+ Can include fonts
+ Is managed like ordinary PDF files
+ Can be protected with a password
+ Can include ICC profile
– Cannot be managed by older layout programs
EPS
+ Commonly used
+ Can be mounted with most layout applicaitons
– Takes up somewhat more memory than illustration application files
– Does not retain all the editorial features of the illustration application
– Different file formats for Mac and Windows
– Requires and illustration or layout program to be viewed
– Only newer file versions can include fonts
Illustrator AI
+ Uses little memory
+ Can use all editing features
+ Can include fonts
+ Can include ICC profiles
– Cannot be managed by all layout programs
WMF and EMF
• Windows Metafile and Enhanced Metafile
• used for simpler object graphics in windows setting
• supported by most office applications
SVG
• Scalable Vector Graphics
• format for object-based images for the web
• not intended for printed documents
DWG and DXF
• short for drawing
• standard format to store drawing files produced with a CAD application
• files can be imported into illustrator
• make up the foundation of packaging design
SWF
• Shockwave File
• object-based animations and interactive images
• created by Flash
• format is web based and not intended for print
Pixel Graphics
An image divided into tiny squares of color (pixels), almost like a mosaic.Creation of Pixel Images
• scanned
• digitally photographed
• created directly on the computer
Applications for Pixel Graphics
• Adobe Photoshop
• Adobe Photoshop Elements
• Intellihance
• Photo Perfect
• Paintshop Pro
• Painter
Color Modes of Pixel Images
Pixel-based images can be black and white or color and contain different numbers of color.line art
• composed of completely black and white
• no mid range tones
• the higher the resolution the better the print quality
examples: one-color logotype, graphic illustrations, screen fonts
grayscale
• composed of pixels in black, white and shades of gray
examples: black and white photos, marker drawings that contain mid-range tones but composed of a single color
duotone
• tinted grayscale images
• made up of two printing inks
Exercise: Creating Duotone Images
four color
• made up of C M Y K
• used to produce full color images in print
• takes up 33% more memory than the same image in RGB
Resolution
Image resolution is determined by two factors:1. The screen frequency you wish to print in
2. Whether or not you need to change the size of the image
The Right Resolution for Images
• images should be 2 x’s in resolution the value of the linescreen they will be printed at.
The Right Resolution for Line Art
• requires much higher resolution
so that image does not appear jagged
• Printing process determines resolution needed
laser and newsprint = 600 – 800 ppi
fine uncoated paper = 800-1200 ppi
fine coated paper = over 1200 ppi
File Formats for Pixel-Based images
Pixel based images can be saved in a number of formats. Some of them have become more or less industry standards. Listed below are some of these popular formats with their pros and cons:PSD
• primary function is image editing stage
• cannot be compressed
TIFF
• tagged image file format
• bitmaps, grayscale, RGB or CMYK images
• can use LZW compression (lossless)
EPS
• encapsulated postscript file
• both object and pixel graphics
• like a font has two parts: low res preview and high res print file
DCS and DCS2
• desktop color separation file
• contains 1 low res preview and 4 additional parts (CMYK)
• DCS2 evolved from DCS
• allows us to save an image in as many parts as colors are used
• can be read by anyone
• handles most color modes and funcitons
• can be compressed to be quite small
JPG
• joint photographic experts group
• compression and quality loss
JPG 2000
• evolved form JPG format
• works for both web and print
• better / higher quality of compressed image
Image Compression
Because pixel based images often take up storage space in the computer, which is for the most part not a big deal, it can become an issue when time to transport images or files via the net.LZW
ZIP
JPG
LZW Compression
Named after the scientists Lemple,Ziv and Welch is a lossless form of compression. Which means:
• when compressed the image will not be ruined
• when used with GS, RGB or CMYK images the file size will be about half
NOTEthis type of compression may cause problems for the printer.
ZIP
• Also lossless
• mainly used for images in or included in PDF format /file.
JPG / JPEG
The most common type of compression method.• not a lossless form of compression
• actually removes information from the image
Capturing & Scanning Images
The way in which an image is acquired will in large part determine it’s level of quality or “usability”.Digital Photography
• Comparison to traditional photography
– good digital cameras are more expensive
– have a poorer dynamic range, more difficulty producing tones
– less sensitive to color temperatures of light
• Marketed based on number of Megapixels camera can capture
• The better the optics the better the image quality
Scanning
A means for transferring original images to the computer for viewing and editing.There are 3 types:
• Drum
• Film
• Flatbed
Drum Scanners
• original art mounted on a glass drum
• large and expensive
• very high quality
• only for flexible media
• good for large volume
Film Scanners
• used for slides or film negatives
• scans only one picture at a time
• similar to drum scanner
Flatbed Scanners
• original art placed on flat glass plate
Good (and Bad) Image Formats
As far as off set printing is concerned, there are only two image formats that you want to “end up with”:1. Tiff or TIF
2. EPS
The “Bad Image Formats” are identified as such because they should not be included in files sent out for offset printing. Identified as:
• RGB images
• GIF images
• JPG images
• below 300 dpi at 100% size (150 is acceptable)
Using TIF Images: GOOD
• multi-layered vs. flat
• managing files and file naming
• only use layered tif files to preserve type in vector format
Using EPS Images: GOOD
• best for vector art or object art
• also used with basic clipping paths
Exercise: Creating A Clipping Path
Image Editing
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