CARTOGRAPHY AND VISUALIZATION II

Lesson 11

By Mwaura Joshua | @openmapsCo on Twitter

Lesson 11: Map reproduction

Map Reproduction

  • This refers to printing of a map, or the electronic duplication of a map
    • Print reproduction refers to the physical printing of a map using inks on paper
    • Electronic reproduction refers to the duplication of a map in digital form

Map Reproduction | Planning

  • 1. Determine the number of maps to be reproduced
    • Reproduction consideration; Printing methods to be used
  • 2. Select a scale and map projection that is appropriate for the map’s theme
    • This forms the foundation of your map
  • Questions to be answered at this stage
    • Who’s the intended audience, & what’s purpose of the map?
    • What is your budget?
    • When is your deadline?
    • What material will be used?
    • Will it be printed in full color or gray tones?

Map Reproduction | Editing

  • The critical evaluation and correction of every aspect of a map
    • This begins the first time the cartographer views the map in its early stages, and culminates just before printing
  • Questions that should be addressed when editing
    • Map design; Does the design appropriately serve the map user? Does it communicate effectively?
    • Completeness; Are any features, map elements, or type labels missing?
    • Accuracy; Are features, map elements, and type labels correctly placed? Are words and numbers correct?

Map Reproduction | Editing

  • Cartographers who edit their own maps face over-familiarity and fatigue, thus, you need
    • Have a separate individual edit the map
    • Edit with fresh eyes, at the beginning of a work session
    • Edit large maps in sections
    • View maps upside-down or sideways
    • Edit after several days of separation from a map
    • Read out loud

Print Reproduction | Screening

  • Screening is a technique that makes colors appear lighter
    • It involves reducing the amount of ink or toner applied to the print medium
    • its used to create tints of a base color, and to represent continuous tone surfaces
  • Two categories of screening
    • Halftone
    • Stochastic

Print Reproduction | Screening: Halftone

  • Used in most print reproduction methods with the exception of ink-jet printing
  • Ink or toner is applied in a pattern of equally spaced dots of variable size
  • Used for pop art movement...
halftone

Print Reproduction | Screening: Stochastic

  • Used primarily with ink-jet printing
  • Ink or toner is applied in a pattern of very small, non-randomly spaced dots of uniform size
Stochastic

Print Reproduction | Aspects of Color Printing

  • Process colors
    • CMYK (subtractive primaries + black)
    • Mixed on the page by applying them, in sequence, to the same area
CMYK

Print Reproduction | Aspects of Color Printing

  • Spot colors
    • Opaque inks that are premixed before they reach the printing device
    • Tints can be created through screening
    • Exact color matches are easier to achieve because they do not rely on the printing device for mixing
spot-color

Print Reproduction | High Volume Print Reproduction

  • When large numbers of maps are required, issues of cost and time become critical
    • Methods for low-volume print reproduction such as laser and ink-jet printing become too costly or time-consuming
    • High-volume reproduction is dominated by a single method:- Offset Lithography

Offset Lithography

  • Lithography is a printing process in which ink sticks only to certain areas of a surface
  • Virtually all mass-produced maps are the result of offset lithography
  • Characterized by excellent print quality and high printing speed
  • Provides a significant decrease in the cost per unit as the number of copies increases
Lithography

Offset Lithography Process

  • 1. Pre-press phase
    • Consists of various technologies and procedures
    • Printing plates and Proofs are produced
  • 2. Printing plate
    • A sheet of aluminium that is mounted on a roller on an offset press, receives a positive, latent (invisible) image that ink sticks to, one for each color

Offset Lithography Process

    • Traditionally created from film negatives, are now replaced by Computer-To-Plate (CTP) technology
plates

Offset Lithography Process

  • Proof
    • A representation of what the final, reproduced map will look like
    • An essential component of the prepress phase, allows editing to ensure that your map will be reproduced just as you intend
    • Various levels of quality/cost
proof

High Volume Print Reproduction

  • File formats for pre-press
    • A digital map can be delivered to the printing house in a variety of formats
    • In the native format of the application software that created it (.MXD, .AI)
    • In a page description language (Postscript)
    • In a portable document format (EPS, PDF)

Offset Lithographic Printing

  • The offset press has one or more printing units that transfer ink to the print medium
  • Each printing unit is capable of printing one base color
printing inks

Offset Lithographic Printing

  • The image is transferred from the printing plate to the blanket cylinder, which then transfers the image onto the print medium
printing cylinder

Offset Lithographic Printing

  • Multi-color print jobs employ multiple printing units, one for each base color
  • The print medium receives a different color ink from each printing unit
printing color

--End of Lecture 11 --

Cartography & Visualization II


That’s it!

Queries about this lesson, please send them to: jmwaura.uni@gmail.com

***References***

  • Mapping, Society, and Technology, Steven Manson
  • Web Cartography, Map Design for Interactive and Mobile Devices, Ian Muehlenhaus
  • Web Cartography, Menno-Jan Kraak and Allan Brown, ITC
  • Cartography, Thematic Map Design, Borden D. Dent
  • GIS Cartography, A Guide to Effective Map Design, Gretchen N. Peterson
  • Thematic Cartography and Geovisualization, Terry A. Slocum et.al
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