MAP REPRODUCTION Cartographic Design for GIS Geog 340

MAP REPRODUCTION Cartographic Design for GIS (Geog. 340) Prof. Hugh Howard American River College

MAP REPRODUCTION • The 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 • I will focus on print reproduction

PLANNING AHEAD

PLANNING AHEAD

PLANNING AHEAD • The following questions need to be answered early in the design process – Who is the intended audience, and what is the 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?

PLANNING AHEAD – – What size will it be? How many copies are required? Will it be folded? What will the pattern be? What level of print or display quality is acceptable? – Will you copyright the map? Will the map infringe on an existing copyright?

MAP EDITING

MAP EDITING • The critical evaluation and correction of every aspect of a map – Begins the first time the cartographer views the map in its early stages, and culminates just before reproduction begins

MAP EDITING • 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 EDITING • Cartographers who edit their own maps face over-familiarity and fatigue – 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 type out loud

RASTER IMAGE PROCESSING for PRINT REPRODUCTION

RASTER IMAGE PROCESSING • The conversion of a digital map into a raster image that can be processed directly by a raster-based printing device

RASTER IMAGE PROCESSING • Printing the digital map

SCREENING for PRINT REPRODUCTION

SCREENING • A technique that makes colors appear lighter – Involves reducing the amount of ink or toner applied to the print medium – Used to create tints of a base color, and to represent continuous tone surfaces

SCREENING • Two categories of screening – Halftone – Stochastic

SCREENING • Halftone screening – 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 Amplitude Modulation (A. M. )

SCREENING • Halftone screening – Helped define the pop art movement…

SCREENING • Stochastic screening – Used primarily with ink-jet printing – Ink or toner is applied in a pattern of very small, pseudo randomly spaced dots of uniform size Frequency Modulation (F. M. )

ASPECTS of COLOR PRINTING

COLOR PRINTING • Process colors – CMYK (subtractive primaries + black) – Mixed on the page by applying them, in sequence, to the same area Cyan + Black Magenta Yellow

COLOR PRINTING • Process colors (cont. ) – Semi-opaque, or translucent, allowing them to combine on the page – Together with screening, allow for the creation of a wide variety of colors – Used in four-color process printing

COLOR PRINTING • Process colors (cont. ) – When mixed on the page, tints of each base color are represented by halftone patterns, each with a unique screen angle Rosette Pattern

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

HIGH VOLUME PRINT REPRODUCTION

HIGH VOLUME PRINT REPRO. • 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

HIGH VOLUME PRINT REPRO. • 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

HIGH VOLUME PRINT REPRO. • Offset Lithography (cont. ) – Provides a significant decrease in the cost per unit as the number of copies increases – Performed on an offset lithographic printing press

HIGH VOLUME PRINT REPRO. • The pre-press phase – Consists of various technologies and procedures that make offset lithographic printing possible – Printing plates are produced – Proofs are produced

HIGH VOLUME PRINT REPRO. • Printing plate – A sheet of aluminum that is ultimately mounted on a roller on an offset press – Receives a positive, latent (invisible) image that ink will stick to

HIGH VOLUME PRINT REPRO. • Printing plate (cont. ) – One is created for each color – Mounted on an offset press, washed with ink, and used to transfer an image onto the print medium Traditionally created from film negatives Replaced by Computer-To-Plate (CTP) technology

HIGH VOLUME PRINT REPRO. • Proof – A representation of what the final, reproduced map will look like – An essential component of the prepress phase – Used in conjunction with editing to ensure that your map will be reproduced just as you intend

HIGH VOLUME PRINT REPRO. • Proof (cont. ) – Various levels of quality/cost

HIGH VOLUME PRINT REPRO. • File formats for pre-press – A digital map can be delivered to the service bureau 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)

HIGH VOLUME PRINT REPRO. • 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

HIGH VOLUME PRINT REPRO. • Offset Lithographic Printing (cont. ) – The image is transferred from the printing plate to the blanket cylinder, which then transfers the image onto the print medium

HIGH VOLUME PRINT REPRO. • Offset Lithographic Printing (cont. ) – Multicolor print jobs employ multiple printing units, one for each base color – The print medium receives a different color ink from each printing unit

MAP REPRODUCTION Cartographic Design for GIS (Geog. 340) Prof. Hugh Howard American River College