MAP REPRODUCTION

Cartographic Design for GIS (Geog. 340)Prof. Hugh HowardAmerican 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 ofCOLOR PRINTING

COLOR PRINTING• Process colors

– CMYK (subtractive primaries + black)– Mixed on the page by applying them, in

sequence, to the same area

Cyan

Magenta Yellow

+ Black

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 HowardAmerican River College