2. CHAPTER 1
Introduction to Engineering Drawing and Design

3. Learning Objectives
Explain topics related to the history of engineering drafting
Define drafter and other related terminology
Identify categories and disciplines related to drafting
Describe the requirements for becoming a drafter

4. Learning Objectives
List and explain points to consider when seeking employment
Identify the professional organization that is dedicated to the advancement of design and drafting
Explain workplace ethics and related issues
Identify topics related to copyrights, patents, and trademarks

5. Engineering Drawing Common language of engineering
Process of creating drawings for any engineering or architectural application

6. Engineering Drawing Also known as: Drafting Engineering drafting
Mechanical drawing
Mechanical drafting
Technical drawing
Technical drafting

7. Engineering Drawings Effective and efficient way to communicate:
Design intent
Engineering requirements
Instructions
Proposals
Typically not open to interpretation

8. Mechanical Drafting Used in the manufacturing industry, or
Heating, ventilating, and air- conditioning (HVAC) systems

9. Manual Drafting
Traditional drafting practice using pencil or ink on a medium such as paper or polyester film
Mostly replaced by computer-aided drafting (CAD)

10. Computers in Design and Drafting
Have revolutionized design and drafting practices
Used in several industries and most engineering and architectural related disciplines for design and drafting

11. Computers in Design and Drafting
Computer-aided design and drafting (CADD)
Computer-aided design (CAD)
Computer-aided drafting (CAD)

12. Early Drawing Practices
Pictograms and petroglyphs
Prehistoric graphic forms of communication
Designers of ancient structures and machines
Sketches, drawings, and documents
14th and 15th century
Engineering drawings representing machines and buildings

13. Early Engineering Drawing Pioneers
Leonardo da Vinci
Italian artist, inventor, and mapmaker
Created pictorial drawings generally without dimensions

14. Leonardo da Vinci

15. Early Engineering Drawing Pioneers
Leon Battista Alberti
Italian architecture and engineering author
Explored the need to incorporate more geometry in drawings
Proposed drawings with multiple views

16. Early Engineering Drawing Pioneers
René Descartes
French inventor of the Cartesian coordinate system
Founder of analytic geometry
Gaspard Monge
French developer of descriptive geometry

17. The Industrial Revolution
Parts produced from hand sketches or hand drawings on blackboards
Coleman Sellers, American engineer and innovator
Henry Ford, American automobile manufacture
Most designs began as a hand sketch of the object to build

18. The Industrial Revolution
Interchangeability became important
Requires accurate drawings
19th century
Engineering drawing evolves more rapidly

19. Early Drafting Practices and Equipment
Drawings created by hand on a board
Initial drawing was done using a pencil, T- square, triangles, scales, irregular (French) curves, compasses, and dividers
Drafters often traced original pencil drawings onto cloth using pen and ink
Attention to lettering quality

20. Drafting Machines
Replaced the T-square, triangles, scales, and protractor
Arm and track (track shown)
Parallel bar

21. Drawing Reproduction
Required for distributing drawings to manufacturers or builders
Blueprints
Replaced by the diazo process
Modern printers, plotters and engineering copiers create prints

22. Computer-Aided Design and Drafting (CADD)
Schools started teaching CADD
1990s
Many schools and companies make the complete transition to CADD
CADD now accounts for almost all design and drafting

23. The Drafter
Prepares technical drawings and plans used by production and construction workers
Fills in technical details using drawings, rough sketches, specifications, and calculations made by engineers, surveyors, architects, or scientists

24. The Drafter
Uses technical handbooks, tables, calculators, and computers
Most often uses computer-aided design and drafting (CADD) systems to prepare drawings

25. Other Common Titles

26. Drafting Fields
Specific drafting areas have unique conceptual and skill characteristics
Drafters often create a variety of drawings even though they may be an employ in a certain field, or focus on a specific product
Drafters often work with a team, individuals of the same discipline, and others related to a specific project

27. Aeronautical Drafter CADD models and drawings
Airplanes
Missiles
Spacecraft
Components and related equipment
Specialization of mechanical drafting

28. Architectural Drafter
CADD models and drawings
Architectural and structural features of a building

29. Architectural Drafter

30. Automotive Design Drafter
Working layouts and master drawings
Automotive vehicle components, assemblies, and systems
Specialization of mechanical drafting

31. Cartographic Drafter Cartographer Maps of geographical areas
Natural and constructed features
Political boundaries
Other features

32. Casting, Forging, and Mold Drafter
CADD models and drawings
Castings
Forgings
Modeled parts
Specialization of mechanical drafting

33. Civil Drafter CADD models and drawings
Construction or civil engineering projects

34. Civil Drafter

35. Commercial Drafter Facilities Drafter
Lays out the location of buildings
Planning of arrangements in offices, large rooms, store buildings, and factories
Specialization of architectural drafting

36. Directional Survey Drafter
Plots oil- or gas-well boreholes
Specialization of civil drafting

37. Electrical Drafter CADD models and drawings Electrical equipment
Wiring diagrams
Circuit board assembly diagrams
Layout drawings

38. Electrical Drafter

39. Electronic Drafter CADD models and drawings
Electronic devices and components
Printed circuit boards
Electronic equipment

40. Electronic Drafter

41. Geological Drafter
Geological or geophysical stratigraphy and locations of gas and oil deposits
Maps
Diagrams
Profiles
Cross sections
Directional surveys
Subsurface formations

42. Geophysical Drafter
Subsurface contours in rock formations

43. Heating, Ventilating, and Air-Conditioning (HVAC) Drafter
HVAC contract documents from engineering schematics
Detail drafter (detailer)

44. Heating, Ventilating, and Air-Conditioning (HVAC) Drafter

45. Industrial Process Pipe Drafter
Industrial Pipe Drafter, Piping Drafter, Pipeline Drafter
CADD models and drawings
Layout, construction, and operation of oil and gas fields, refineries, chemical plants, and process piping systems
Oil and gas drafter

46. Industrial Process Pipe Drafter

47. Landscape Drafter
CADD models and drawings
Landscape architecture

48. Mechanical Drafter Engineering Drafter
Mechanical drafting for the manufacturing industry

49. Mechanical Drafter

50. Marine Drafter CADD models and drawings
Structural and mechanical features of ships, docks, and other marine structures and equipment
Specialization of mechanical and structural drafting

51. Patent Drafter
Clear and accurate drawings of varied sorts of mechanical devices
Used by patent lawyer to obtain patent rights

52. Photogrammetrist Analyzes source data and prepares: Mosaic prints
Contour-map profile sheets
Related cartographic materials

53. Plumbing Drafter Pipe Drafter CADD models and drawings
Installation of plumbing and piping equipment for residential, commercial, and industrial installations
Closely related to industrial process pipe drafting

54. Structural Drafter CADD models and drawings Detail drafter (detailer)
Structures employing structural reinforcing steel, concrete, masonry, wood, and other structural materials
Detail drafter (detailer)

55. Structural Drafter

56. Technical Illustrator
Lays out and draws illustrations for:
Reference works
Brochures
Technical manuals

57. Technical Illustrator

58. Tool and Die Design Drafter
CADD models and detailed drawing plans for manufacture of tools
Specialization of mechanical drafting

59. Education and Qualifications
Postsecondary training in a drafting program
Considerable experience with CADD systems and techniques
Strong background in drafting principles
Ability to apply knowledge to a broader range of responsibilities
Mechanical ability and visual aptitude

60. Education and Qualifications
Ability to perform detailed work accurately
Good interpersonal skills
Knowledge of:
Drafting standards
Mathematics
Science
Engineering technology
Manufacturing
Construction methods

61. Advancement Entry-level or junior drafters Intermediate drafters
Senior drafter, designer, or supervisor
Opportunities include design, checking, purchasing, estimating, and management

62. Drafting Job Opportunities
Fluctuate with national and local economies
Tied to industries that are sensitive to cyclical changes in the economy
Construction
Manufacturing
Increasing temporary or contract employment

63. Drafting Job Opportunities
Mechanical drafting
Metropolitan areas where manufacturing is strong
Civil or structural drafting
Areas that are more rural
Electronic data transfer helps to create a broader range of opportunities

64. Searching For a Drafting Position
Education and training requirements vary with job opportunities and employer requirements
Two-year, post-secondary degree advantage
Cooperative work experience (CWE) or internship

65. Job-Seeking Strategy Get your resume in order
Write an application or cover letter
Prepare a portfolio
Register with employment services
Use internet resources

66. Job-Seeking Strategy Be realistic Research prospective companies
Be prepared when you get an interview
Ask intelligent questions
Respond fast to job leads
Make a decision with enthusiasm
Send thank-you letters

67. Salaries and Employment Benefits
Comparable to salaries of other professions with equal educational requirements
Employment benefits are common and vary according to each employer

68. ADDA International American Design Drafting Association, and
American Digital Design Association
Dedicated to the advancement of design and drafting and the graphics professions across all industries

69. ADDA International Leadership opportunities Certification program
Certified curriculum program
Professional councils and student chapters
Annual Design Drafting Week, Technical and Educational Conference, and poster and design drafting contest
Product and publication approval
Publications
Employment Center

70. Drafting Standards
Established in most industries, schools, and companies
Promote safety, reliability, quality, productivity, interchangeability, and efficiency
Lowers costs and simplifies training
Code

71. Drafting Standards Apply to: CADD file storage, naming, and backup
File templates
Units of measurement
Layout characteristics
Borders and title blocks
Symbols
Layers, and text, table, dimension, and other drafting styles
Plot styles and plotting

72. Common Engineering Drawing and Design Standards
American Society of Mechanical Engineers (ASME) standards
Accredited by the American National Standards Institute (ANSI)
American Welding Society (AWS) standards
CADD Skill Standards
International Organization for Standardization (ISO) standards
United States National CAD Standard (NCS)

73. Workplace Ethics Elements of a code of ethics: Be dependable
Obey the laws
Be good to customers

74. Intellectual Property Rights
Protecting product research, engineering, and development
Employees must help protect design ideas and trade secrets
Proprietary notes on drawings

75. Software Piracy It is against the law to share copies of some software
Use software legally and report illegal use when observed

76. Copyrights Control exclusively the reproduction and distribution of:
Literary, musical, and dramatic works
Pictorial, graphic, and sculptural works
Motion pictures and other audiovisual works
Sound recordings
Architectural and certain other intellectual works

77. Patents
20-year term
U.S. patent grants effective only within the U.S., U.S. territories, and U.S. possessions
Subject matter must be useful

78. Application for a Patent
Nonprovisional Application for a Patent
Provisional Application for a Patent

79. Patent Drawings Form an integral part of a patent application
Must show every feature of the invention

80. Trademarks Different from a copyright or a patent
Rights start from the actual use of the mark
Federal registration not required, but offers advantages
Service mark

81. Glossary Analytic geometry Arm drafting machine Blueprint
The link between algebra and geometry.
Arm drafting machine
A drafting machine with arms attached to a mounting bracket at the top of the table. The arms control the movement of the head.
Blueprint
An early contact chemical-printing process of a drawing or other image copied on paper with white lines on a blue background.

82. Glossary Board Cartesian coordinate system Code
An early drafting table.
Cartesian coordinate system
A measurement system that uses numerical coordinates to locate points in space according to distances measured in the same unit of length from three intersecting axes.
Code
Standard that one or more governmental bodies adopts and has the force of law.

83. Glossary Code of ethics Computer-aided design (CAD)
A formal document that states an organization’s values and the rules and principles that employees are expected to follow.
Computer-aided design (CAD)
Uses computers for design.
Computer-aided design and drafting (CADD)
The process of using a computer with CADD software for design and drafting applications.

84. Glossary Computer-aided drafting (CAD) Copyright Descriptive geometry
Uses computers for drafting.
Copyright
The legal rights given to authors of original works of authorship.
Descriptive geometry
The system of graphic geometry that uses plane projections to describe and analyze their properties for engineering drafting applications.

85. Glossary Detail drafter (detailer) Diazo
Works for a structural contractor developing 3-D models, detailed shop drawings and installation drawings, performing trade-to-trade coordination to a finished degree and developing fabrication drawings. Detailers may also be involved in download to or input into a structural component fabrication software.
Works for an HVAC contractor developing 3-D models, detailed shop drawings and installation drawings, performing trade-to-trade coordination to a finished degree and developing fabrication cutsheets.
Diazo
Creates blue line copies with a white background.

86. Glossary Drafter Drafting Drafting machine
A man or woman employed in the drafting profession.
Drafting
A graphic language using lines, symbols, and notes to describe objects for manufacture or construction.
Drafting machine
A machine that mounts to the table or board and has scales attached to an adjustable head that rotates for drawing angles. When locked in a zero position, the scales allow drawing horizontal and vertical lines and perpendicular lines at any angle orientation.

87. Glossary Ethics File template Interchangeability Oil and gas drafter
Rules and principles that define right and wrong conduct.
File template
A file that contains standard file settings and objects for use in new file.
Interchangeability
Parts manufactured identically within given tolerances. Interchangeable parts are produced to specifications that make sure they are so nearly identical that they will fit into any product for which they are designed.
Oil and gas drafter
An industrial process pipe drafter who specializes in oil and gas industrial pipe drafting.

88. Glossary Parallel bar Patent Petroglyphs
A long horizontal drafting edge attached to each side of the table and moves up and down on the table. The parallel bar allows the drafter to draw horizontal lines and triangles are used on the bar for drawing angled lines.
Patent
The grant of a property right to the inventor of an invention, issued by the United States Department of Commerce, United States Patent and Trademark Office (USPTO).
Petroglyphs
Prehistoric carvings.

89. Glossary Pictograms Service mark Software piracy
Prehistoric drawings and paintings.
Service mark
The same as a trademark except that it identifies and distinguishes the source of a service rather than a product.
Software piracy
The unauthorized copying of software.

90. Glossary Standards Track drafting machine Trademark
Guidelines that specify drawing requirements, appearance, and techniques, operating procedures, and record keeping methods.
Track drafting machine
A drafting machine with a traversing track that mounts to the table and a vertical track that moves along the horizontal track. The machine head traverses vertically on the track.
Trademark
A word, phrase, symbol or design, or combination of words, phrases, symbols or designs, that identifies and distinguishes the source of the goods or services of one party from those of others.

91. CHAPTER 2
Drafting Equipment, Media, and Reproduction Methods

92. Learning Objectives
Describe and demonstrate the use of manual drafting equipment and supplies
Explain the concept of drawing scale, and identify common inch and metric scales
Read metric, civil engineer, architect, and mechanical scales

93. Learning Objectives
Describe and use drafting media, sheet sizes, and sheet blocks and symbols
Explain common drawing reproduction methods

94. Manual Drafting (Hand Drafting)
Mostly replaced by computer-aided design and drafting (CADD)
Manual drafting and CADD require understanding the basics of drafting
Scale
Sheet size
Sheet format

95. Manual Drafting Equipment and Supplies
Historical reference
Still valuable for:
Sketching
Taking measurements
Other related activities
Still used by some companies for certain applications

96. Automatic Pencils
Common for manual drafting, sketching, and office use
Do not require sharpening
Available in several different lead sizes
Combination of 0.5, 0.7, and 0.9 mm pencils and leads good for sketching and daily use

97. Lead Grades Different grades of hardness for specific techniques
2H and H good for typical daily office use
2H to F for thick lines
4H to H for thin lines
6H or 4H for construction lines and guidelines

98. Compasses

99. Dividers
Bow
Proportional

100. Parallel Bar Draw horizontal lines
Use triangles to draw vertical lines and angles

101. Triangles Straightedge Draw angles Connect points 30°–60° triangle
Angles of 30°–60°–90°
45° triangle
Angles of 45°–45°–90°

102. Templates Circles Ellipses Letters
Specific requirements and drafting disciplines
Examples:
Architectural symbols
Electronic schematic symbols

103. Irregular Curves Have no constant radii French and flexible curves
Radius curve

104. Drafting Machines
Generally take the place of triangles and parallel bars
Maintains a horizontal and vertical relationship between scales
Scales serve as straightedges
Protractor allows scales to be set quickly at any angle

105. Arm and Track Drafting Machines

106. Scale Measurement instrument
Specific scales for mechanical, architectural, civil, and metric drawings
Used by manual drafters to help create scaled drawings
Still useful for sketching, taking measurements, and related tasks
Four basic shapes

107. Scale
Concept
A universal and critical design and drafting concept

108. Drawing Scale
Drawings are scaled so the objects represented can be illustrated clearly on standard sizes of paper
Depends on:
Actual size of the objects drawn
Amount of detail to show
Media size
Amount of dimensioning and notes required

109. Inch Mechanical Drawing Scales
Full scale = FULL or 1:1
Half scale = HALF or 1:2
Quarter scale = QUARTER or 1:4
Twice scale = DOUBLE or 2:1
Four times scale = 4:1
Ten times scale = 10:1

110. Drawing Scale

111. Metric Mechanical Drawing Scales
Full scale = 1:1
Half scale = 1:2
One fifth scale = 1:5
One twenty-fifth scale = 1:25
One thirty-three and one-third scale = 1:33 1/3
One seventy-fifth scale = 1:75

112. U.S. Customary Architectural Drawing Scales
1/8" = 1'–0"
1/4" = 1'–0"
1/2" = 1'–0"
1" = 1'–0"
1 1/2" = 1'–0"
3" = 1'–0"

113. U.S. Customary Civil Drawing Scales
1" = 10'
1" = 20'
1" = 30'
1" = 50'
1" = 60'
1" = 100'

114. Metric Scale Any scale is a multiple of ten
Any reductions or enlargements are easy to perform
No mathematical calculations should be required

115. Civil Engineer’s Scale
Divisions
Ratio
Scales Used with This Division 10
1:1
1" = 1"
1" = 1'
1" = 10'
1" = 100' 20
1:2
1" = 2"
1" = 2'
1" = 20'
1" = 200' 30
1:3
1" = 3"
1" = 3'
1" = 30'
1" = 300' 40
1:4
1" = 4"
1" = 4'
1" = 40'
1" = 400' 50
1:5
1" = 5"
1" = 5'
1" = 50'
1" = 500' 60
1:6
1" = 6"
1" = 6'
1" = 60'
1" = 600"

116. Civil Engineer’s Scale
Any multiple of ten
10 scale often used for mechanical drawings at full, decimal-inch scale (1:1)
20 scale common for mechanical drawings at half scale (1:2)
20 scale used for scales of 1" = 2', 1" = 20', and 1" = 200'
50 scale popular in civil drafting

117. Architect’s Scale 11 different scales Ten of the scales Eleventh scale
Inch represents a specific increment of feet
Feet subdivided into multiples of 12 parts to represent inches and fractions of an inch
Eleventh scale
Full scale divided into 16 parts, each part equal to 1/16 of an inch

118. Mechanical Engineer’s Scale
Common for mechanical drawings in fractional or decimal inches
Full-scale divisions divided into 1/16, 10, and 50

119. Vellum Most common drafting media Inexpensive
Good smoothness, erasability, and transparency
Less durable and dimensionally stable
Appropriate for regular graphite leads
Well drawn graphite on vellum reproduces well

120. Polyester Film Mylar® Expensive
Excellent durability, smoothness, erasability, dimensional stability, and transparency
Best with ink or special polyester leads
Well drawn ink on polyester film reproduces the best

121. Sheet Size and Format Standards for sheet size and format
ASME Y14.1, Decimal Inch Drawing Sheet Size and Format
ASME Y14.1M, Metric Drawing Sheet Size and Format
Architectural, civil and structural drawings often use unique sheet format and may use unique sheet sizes

122. ASME Inch Sheet Size and Format
[Insert Figure 2.31]

123. ASME Metric Sheet Size and Format

124. Selecting a Sheet Size Size of objects drawn Drawing scale
Amount of additional content on the sheet
Border
Title block
Drafting standards and company practice

125. G, H, J, and K apply to specific roll sizes
ASME Inch Sheet Sizes
Size Designation
Size in Inches
Vertical
Horizontal A
8 1/2
11 (horizontal format) 11
8 1/2 (vertical format) B 17 C 22 D 34 E 44 F 28 40
G, H, J, and K apply to specific roll sizes

126. ASME Metric Sheet Sizes
Size Designation
Size in Millimeters
Vertical
Horizontal A0
841
1189 A1
594 A2
420 A3
297 A4
210
A1.0, A2.1, A2.0, A3.2, A3.1, and A3.0 apply to specific elongated sizes

127. Line Format Specified in ASME Y14.2M, Line Conventions and Lettering
Thick lines of 0.6 mm (.02 in.)
Borders
Outline of principle blocks
Main divisions of blocks
Thin lines of 0.3 mm (.01 in.)
Dividing parts lists and Revision History blocks
Minor subdivisions of the title block and supplementary blocks

128. ASME Lettering Style Vertical uppercase Gothic
Arial, Roman, or similar font when using CADD

129. ASME Letter Heights Sheet Elements Minimum Letter Heights INCH
Drawing Sizes INCH
Letter Heights METRIC (mm)
Drawing Sizes METRIC
Drawing title, sheet size, CAGE Code, drawing number, revision letter in the title block
.24
D, E, F, H, J, K 6
A0, A1
.12
A, B, C, G 3
A2, A3, A4
Zone letters and numbers in borders
All sizes
Drawing block headings
.10
2.5
All other characters

130. Border Format margin of a sheet
Borderlines form a rectangle to establish the border
ASME minimum distance from the edges of the sheet to borderlines:
.5 in. for all inch drawing sheet sizes
20 mm for A0- and A1-size sheets
10 mm for A2-, A3-, and A4-size sheets

131. Zoning Allows the drawing to read like a road map
Recommend by ASME standards for all sheets
Optional for A, B, and A4 size sheets

132. Title Block

133. ASME Title Block

134. Angle of Projection Block
Third angle projection
First angle projection

135. Dimensioning and Tolerancing Block

136. Revision History Block
Zone
Revision
Description
Date
Approval

137. Revision Status of Sheets Block
Not required on single-sheet drawings
Horizontal or vertical
Located by the title block or in the area of the Revision History block

138. Revision Status Notation
ALL SHEETS ARE THE SAME REVISION STATUS
Optional
Next to the title block when the revision status of all sheets is the same

139. Additional Sheet Blocks and Symbols
Margin drawing number block
Application block
Microfilm alignment arrows

140. Diazo Reproduction Ozalid dry prints or blue-line prints
Not an actual blueprint
Mostly replaced by photocopy reproduction and CADD prints

141. Photocopy Reproduction
Photocopy printers or engineering copiers
Photographically reproduces material, especially by xerography
Advantages over diazo printing

142. Properly Folding Prints

143. Glossary Angle of projection block Application block Automatic pencil
Specifies how to interpret a drawing according to the method of view projection.
Application block
Includes information such as next assembly and where used for drawings of a detail part or assembly of a component of a larger assembly.
Automatic pencil
A pencil with a lead chamber that advances the lead from the chamber to the writing tip by the push of a button or tab when a new piece of lead is needed.

144. Glossary CAGE Code Compass Dimensioning and tolerancing block
A five number code assigned by the United States Defense Logistic Service Center (DLSC) to all Department of Defense contractors. CAGE stands for Commercial And Government Entity.
Compass
An instrument used to draw circles and arcs.
Dimensioning and tolerancing block
Specifies the general dimensioning and tolerancing specifications found on the drawing.

145. Glossary Dividers Drafting machine Ellipse
Used to transfer dimensions or to divide a distance into a number of equal parts. Dividers are also used in navigation to measure distance in nautical miles.
Drafting machine
A machine that mounts to the table or board and has scales attached to an adjustable head that rotates for drawing angles.
Ellipse
A circle seen at an angle.

146. Glossary Manual drafting (hand drafting) Margin drawing number block
Traditional drafting practice using pencil or ink on a medium such as paper or polyester film, with the support of drafting instruments and equipment.
Margin drawing number block
Identifies the drawing number and sheet number, and optional revision, when reading the margin information on the drawing.
Media
The material upon which you create drawings, such as paper or polyester film.

147. Glossary Microfilm Proportional dividers Revision History block
A film on which drawings or other printed materials are photographed at greatly reduced size for ease of storage and sending from one place to another. When needed, equipment is available for enlargement of the microfilm to a printed copy.
Proportional dividers
Used to reduce or enlarge an object without the need of mathematical calculations or scale manipulations.
Revision History block
Also called the revision block, is used to record changes to the drawing.

148. Glossary Revision status of sheets block Scale Templates
Appears on the first sheet of multiple sheet drawings and records the revision status of each drawing.
Scale
An instrument with a system of ordered marks at fixed intervals used as a reference standard in measurement. A scale establishes a proportion used in determining the dimensional relationship of an actual object to the representation of the same object on a drawing.
Templates
Plastic sheets with accurate shapes cut out and are used as a stencil for drawing the shapes.

149. Glossary Vellum Xerography Zoning
Drafting paper with translucent properties that is specially designed to accept pencil or ink.
Xerography
A dry photographic or photocopying process in which a negative image formed by a resinous powder on an electrically charged plate is electrically transferred to and fixed as positive on a paper or other copying surface.
Zoning
A system of numbers along the top and bottom margins and letters along the left and right margins.