Simple vs. Complex CAD Linetypes: Features, Syntax and Use Cases

A CAD linetype controls the visual pattern displayed along a line, polyline, arc, circle or other compatible drawing object. Depending on its definition, a linetype may contain dashes, dots, blank spaces, text or graphical symbols.

CAD linetypes fall into two main categories:

  • Simple linetypes, made only from dashes, spaces and dots
  • Complex linetypes, which add text characters or shapes to the pattern

Simple linetypes are commonly used for hidden edges, centerlines, boundaries and construction geometry. Complex linetypes are better suited to utility networks, fences, pipelines and other objects that need to display repeated labels or symbols.

This guide explains the features, LIN file syntax, advantages, limitations and practical uses of simple and complex CAD linetypes.

What Is a CAD Linetype?

A linetype is a repeating visual pattern assigned to a CAD object or layer. It changes how the object appears without changing its geometry.

A dashed line, for example, remains a complete geometric line. The linetype simply controls which parts of that line are visible and which parts appear as spaces.

Linetypes can be assigned directly to objects, but in a standardized drawing they are normally controlled through the object’s layer using the ByLayer property.

How Linetypes Control Object Appearance

A linetype pattern can contain several elements:

  • Visible dashes
  • Blank spaces
  • Dots
  • Text strings
  • SHX shapes

These elements repeat along the object according to the definition stored in the linetype.

The final appearance also depends on:

Linetype Definition Files and the LIN Format

Custom linetypes are normally defined in a plain-text file with the .LIN extension.

Each linetype definition contains at least two separate lines:

  1. A header line beginning with an asterisk
  2. A pattern line beginning with A,

For example:

*DASHED,Dashed line
A,.50,-.25

The line beginning with A, must be placed on a new line. Combining the header and the pattern on one line creates an invalid definition that may fail to load.

A LIN file can contain one linetype or an entire library of definitions. After a linetype is loaded, its definition is stored in the drawing. The original LIN file is still needed when the same linetype must be loaded into other drawings.

Complex linetypes may also depend on external resources such as:

  • Text styles
  • SHX fonts
  • SHX shape files
  • Support-file search paths

Simple and Complex Linetypes at a Glance

Feature Simple Linetype Complex Linetype
Pattern elements Dashes, dots and spaces Dashes, spaces, text or shapes
LIN syntax difficulty Low Medium to high
External dependencies Normally none May require styles, fonts or SHX files
Common applications Hidden, center and dashed lines Utilities, fences and labeled systems
Portability High Depends on supporting resources
Maintenance Easy Requires more control
Display problems Uncommon More likely when files or styles are missing
Best environment Any CAD workflow Controlled CAD standards environment

What Is a Simple CAD Linetype?

A simple CAD linetype contains only numerical pattern elements. These values define the length of visible dashes, spaces and dots.

It does not contain text or inserted shapes.

Simple linetypes are lightweight, easy to edit and generally reliable when DWG files are exchanged between different users or CAD applications.

Main Features of Simple Linetypes

A simple linetype offers:

  • A repeating sequence of dashes and spaces
  • Optional points within the sequence
  • No text-style dependency
  • No custom SHX shape dependency
  • Simple plain-text syntax
  • Good compatibility between CAD platforms
  • Easy troubleshooting and maintenance

Simple linetypes are suitable when the line only needs a distinct graphical appearance.

Basic Syntax of a Simple LIN Definition

A basic dashed linetype can be written as follows:

*DASHED,Dashed line
A,.50,-.25

The first line is the header:

*DASHED,Dashed line
  • *DASHED is the linetype name.
  • Dashed line is the description shown in the linetype manager.

The second line is the pattern:

A,.50,-.25
  • A identifies the standard alignment mode.
  • .50 creates a visible dash measuring 0.50 drawing units.
  • -.25 creates a blank space measuring 0.25 drawing units.

The pattern repeats along the selected object.

Autodesk defines simple custom linetypes as patterns made from dashes, dots and spaces, with positive values representing dashes, negative values representing spaces and zero representing a dot. (Autodesk Aide)

Understanding Positive, Negative and Zero Values

The numerical values in a simple linetype have three basic meanings.

Positive values create visible dashes

.50

This value creates a visible segment measuring 0.50 units before scale factors are applied.

Negative values create blank spaces

-.25

This value creates an empty space measuring 0.25 units.

Zero values create dots

0

A dash-dot pattern can therefore be written as:

*DASH_DOT,Dash dot line
A,.50,-.20,0,-.20

The pattern contains:

  1. A visible dash
  2. A blank space
  3. A dot
  4. Another blank space

Common Examples of Simple CAD Linetypes

Simple linetypes include:

  • Dashed lines
  • Hidden lines
  • Centerlines
  • Phantom lines
  • Dotted lines
  • Dash-dot lines
  • Construction lines
  • Boundary lines
  • Projection lines

A basic centerline definition may look like this:

*CENTER,Center line
A,1.25,-.25,.25,-.25

This pattern contains a long dash followed by a space, a short dash and another space.

A dotted line can be defined as:

*DOTTED,Dotted line
A,0,-.20

Best Use Cases for Simple Linetypes

Simple linetypes are appropriate for:

  • Hidden mechanical edges
  • Axes and centerlines
  • Construction geometry
  • Existing or proposed objects
  • Demolition work
  • Alternate component positions
  • Movement paths
  • Property boundaries
  • Survey limits
  • Overhead architectural elements
  • Projection and reference lines

They are generally the best choice when compatibility, simplicity and easy maintenance are more important than embedded labels or symbols.

What Is a Complex CAD Linetype?

A complex CAD linetype combines ordinary dashes and spaces with either text characters or graphical shapes.

For example, a utility linetype may repeat the word GAS along a dashed line. A fence linetype may repeat a custom symbol stored in an SHX file.

Complex linetypes make a drawing easier to interpret because information is built directly into the line pattern.

Main Features of Complex Linetypes

Complex linetypes may contain:

  • Repeated labels
  • Abbreviations
  • SHX characters
  • Custom graphical shapes
  • Text or shape scaling
  • Rotation parameters
  • Horizontal offsets
  • Vertical offsets

They are especially useful when several systems have similar geometry and must remain distinguishable on screen and in monochrome prints.

The Two Main Types of Complex Linetypes

Complex linetypes are divided into two main groups.

Text-Based Complex Linetypes

A text-based complex linetype inserts a word, letter or abbreviation into the repeating pattern.

Typical applications include:

  • Utility lines
  • Pipe systems
  • Electrical networks
  • Fire-protection systems
  • Communication routes
  • Existing and proposed services

Text-based linetypes are usually easier to create and maintain than shape-based definitions.

Shape-Based Complex Linetypes

A shape-based complex linetype inserts a graphical element stored in an SHX shape file.

It can be used for:

  • Fence markers
  • Railway symbols
  • Circular markers
  • Directional arrows
  • Zigzag symbols
  • Specialized engineering patterns

A shape-based linetype requires access to the correct SHX file and the correct shape name within that file.

Syntax of Text-Based Complex Linetypes

A text-based complex linetype includes a bracketed text expression inside the pattern.

Example:

*GAS_LINE,Gas line ---- GAS ---- GAS ----
A,.50,-.20,["GAS",STANDARD,S=.10,U=0.0,X=-.10,Y=-.05],-.25

The first line contains the name and description. The second line contains the pattern.

The text element is:

["GAS",STANDARD,S=.10,U=0.0,X=-.10,Y=-.05]

How the Text Element Is Defined

Each part of the bracketed expression has a specific purpose.

Text string

"GAS"

This is the text displayed in the linetype.

Text style

STANDARD

This is the name of the text style used to display the characters.

The referenced style must exist in the drawing.

Text scale

S=.10

The S= value controls the size of the text relative to the linetype pattern.

The final displayed size is also affected by the drawing’s linetype-scale settings.

Upright rotation

U=0.0

The U= parameter keeps the text upright and easy to read, regardless of the direction in which the line or polyline was drawn.

This is normally the preferred rotation option for labels that must remain readable from the bottom or right side of the drawing.

Horizontal offset

X=-.10

The X= value moves the text along the direction of the line.

It is commonly used to control the distance between the preceding dash and the text.

Vertical offset

Y=-.05

The Y= value moves the text perpendicular to the line.

It can be used to center the characters visually on the object.

Text Rotation Options: U=, R= and A=

Complex linetypes support three main rotation controls:

  • U= for upright rotation
  • R= for relative rotation
  • A= for absolute rotation

Autodesk documents U= as the upright or easy-to-read option, R= as rotation relative to the line and A= as rotation relative to the drawing origin. (Autodesk Aide)

Upright Rotation with U=

Example:

U=0.0

The U= option follows the line while automatically adjusting the text to prevent it from appearing upside down.

It is well suited to:

  • Utility labels
  • Network abbreviations
  • Curved polylines
  • Lines drawn in opposite directions
  • Plans where readability is more important than exact tangential orientation

A practical text-based definition using upright rotation is:

*WATER_LINE,Water line ---- WATER ----
A,.60,-.15,["WATER",STANDARD,S=.10,U=0.0,X=-.10,Y=-.05],-.20

Relative Rotation with R=

Example:

R=0.0

The R= option rotates the characters relative to the direction of the line.

The text follows the local angle of the object, but it may become reversed or upside down when the object direction changes.

Example:

*PIPE_RELATIVE,Pipe line with relative text
A,.50,-.15,["PIPE",STANDARD,S=.10,R=0.0,X=-.05,Y=-.05],-.20

Use R= when the text must follow the exact direction of the line and reversed orientation is acceptable or controlled.

Absolute Rotation with A=

Example:

A=0.0

The A= option maintains a fixed angle relative to the drawing coordinate system.

With A=0.0, the text remains horizontal instead of following the line direction.

Example:

*PIPE_HORIZONTAL,Pipe line with horizontal text
A,.50,-.15,["PIPE",STANDARD,S=.10,A=0.0,X=-.05,Y=-.05],-.20

This option can be useful when all labels must maintain one fixed orientation. It should be tested carefully on vertical lines, curved objects and rotated drawings.

Rotation Units

Rotation values can be expressed in:

  • Degrees
  • Radians
  • Grads

Degrees are the default. Unit suffixes may also be used where supported:

U=0.0d
R=0.0r
A=0.0g

For most standard linetypes, a value of 0.0 is sufficient.

Text Style and Font Dependencies

A text-based linetype refers to a text style, not directly to a font.

The text style then refers to an SHX or TrueType font.

If the required style or font is missing:

  • The linetype may fail to load.
  • The text may not appear.
  • A substitute font may be used.
  • The character dimensions may change.
  • The text may overlap the surrounding dashes.

Use a Text Style with a Height of 0.0

The text style used by a complex linetype should normally have a fixed height of 0.0.

This allows the text size to be controlled by the S= parameter in the LIN definition.

A fixed text height entered in the style can multiply or override the expected result and produce text that is much too large or too small.

Recommended setup:

  1. Create a dedicated text style for complex linetypes.
  2. Assign an approved font.
  3. Set the style height to 0.0.
  4. Control the character size with S=.
  5. Avoid modifying the style after the linetypes have been deployed.

Autodesk support documentation also recommends careful control of text styles and linetype scale when creating complex linetypes. (Autodesk Aide)

Syntax of Shape-Based Complex Linetypes

A shape-based linetype replaces the text expression with a reference to an SHX shape.

Example:

*FENCE_LINE,Fence line with circular markers
A,.40,-.10,[CIRC1,ltypeshp.shx,S=.10,U=0.0],-.10

The shape reference is:

[CIRC1,ltypeshp.shx,S=.10,U=0.0]

How Shape References Work

A shape reference can contain:

  • The shape name
  • The SHX file name
  • A scale value
  • A rotation value
  • Horizontal and vertical offsets

A more detailed example is:

*FENCE_DETAIL,Fence line with adjusted markers
A,.40,-.10,[CIRC1,ltypeshp.shx,S=.10,U=0.0,X=0.0,Y=-.05],-.10

Shape name

CIRC1

This identifies the shape stored in the SHX file.

SHX file name

ltypeshp.shx

This identifies the file containing the compiled shape.

The file must be located in a folder accessible through the CAD application’s support-file search path.

Scale

S=.10

This controls the displayed size of the shape.

Rotation and offsets

The U=, R=, A=, X= and Y= parameters can control the orientation and position of the shape.

SHP and SHX Files Explained

A custom shape normally begins in an editable SHP source file.

The SHP definition is then compiled into an SHX file, which can be read by AutoCAD and other compatible applications.

The usual workflow is:

  1. Create or edit the SHP source.
  2. Compile it into an SHX file.
  3. Reference the shape and file in a LIN definition.
  4. Place the SHX file in an approved support folder.
  5. Load and test the linetype.

An SHX file may contain:

  • Font characters
  • Graphical shapes
  • Symbols used in complex linetypes

A font SHX file and a shape SHX file do not necessarily serve the same purpose. The required shape must exist in the file referenced by the LIN definition.

Problems Caused by Missing Shape Files

If the required SHX file cannot be found:

  • The symbol may disappear.
  • Only the dash pattern may remain visible.
  • The linetype may not load.
  • A missing-file warning may appear.
  • The drawing may look different on another computer.

Custom shape-based linetypes should therefore be distributed with:

  • The LIN file
  • The required SHX file
  • Installation instructions
  • A sample drawing
  • Compatibility notes

Simple vs. Complex Linetype Syntax Comparison

Syntax Element Simple Linetype Complex Text Linetype Complex Shape Linetype
Positive number Visible dash Visible dash Visible dash
Negative number Blank space Blank space Blank space
Zero Dot Dot Dot
Bracketed expression No Text definition Shape definition
Text style required No Yes No
Font dependency No Usually No
Shape-file dependency No No Yes
Scale parameter Not inside an element S= S=
Rotation parameters Not required U=, R= or A= U=, R= or A=
Position parameters Not required X= and Y= X= and Y=
Portability High Medium to high Medium
Editing difficulty Low Medium High

The three basic forms are:

Simple linetype

*CUSTOM_DASH,Custom dashed line
A,.50,-.25

Text-based complex linetype

*GAS_LINE,Gas line ---- GAS ----
A,.50,-.20,["GAS",STANDARD,S=.10,U=0.0,X=-.10,Y=-.05],-.25

Shape-based complex linetype

*FENCE_LINE,Fence line with circular markers
A,.40,-.10,[CIRC1,ltypeshp.shx,S=.10,U=0.0],-.10

Practical Use Cases by CAD Discipline

Architectural Drawings

Simple linetypes are commonly used for:

  • Hidden structural elements
  • Overhead cabinets
  • Beams above the cut plane
  • Demolition work
  • Existing construction
  • Property lines
  • Setback limits
  • Ceiling elements
  • Alternate door positions

Complex linetypes may be used for fences, specialized boundaries and services shown on architectural site plans.

Some elements, such as insulation, may be better represented with a hatch pattern or a dedicated object rather than a linetype.

Civil Engineering and Surveying

Civil and survey drawings frequently use complex linetypes for:

  • Water systems
  • Gas networks
  • Sanitary sewers
  • Stormwater systems
  • Electrical services
  • Communication routes
  • Easements
  • Rights-of-way

Repeated text makes each network identifiable without relying entirely on object color.

Simple linetypes remain suitable for boundaries, proposed alignments, construction limits and existing features.

Mechanical Drafting

Simple linetypes are normally used for:

  • Hidden edges
  • Centerlines
  • Phantom positions
  • Motion paths
  • Alternative component positions
  • Symmetry axes

Complex definitions may identify process piping, hydraulic systems, pneumatic systems or specialty services.

Electrical and MEP Drawings

Complex linetypes can identify:

  • Power circuits
  • Fire-alarm systems
  • Data routes
  • Security networks
  • Chilled-water piping
  • Refrigerant lines
  • Compressed-air systems

Simple patterns may be used to distinguish existing, proposed, hidden or demolished systems.

Linetypes may represent:

  • Roads
  • Railways
  • Pipelines
  • Utility corridors
  • Administrative boundaries
  • Environmental zones
  • Flood limits
  • Municipal limits

Complex linetypes should be tested before data is exported to another CAD or GIS format because text, shapes and rotation settings may not transfer identically.

Advantages and Limitations of Simple Linetypes

Advantages

Easy to create

A simple definition requires only a name, description and numerical pattern.

Easy to edit

Dash and space values can be changed directly in a plain-text editor.

High portability

Simple linetypes normally have no external font or shape dependencies.

Good compatibility

Basic dash patterns are widely supported by DWG-compatible applications.

Easy maintenance

There are fewer files and settings to manage.

Reliable plotting

Simple patterns normally provide consistent results in monochrome and color output.

Limitations

Limited information

A simple pattern cannot directly identify what the line represents.

Similar patterns may be confused

Several systems may look alike when their colors are removed during plotting.

Separate labels may be required

Text or leaders may need to be added manually to explain the object.

Reduced symbol capability

A simple linetype cannot contain repeated words or custom shapes.

Advantages and Limitations of Complex Linetypes

Advantages

Direct identification

Text or symbols reveal the function of the object directly on the drawing.

Fewer manual labels

The identifier repeats automatically along the geometry.

Better monochrome readability

The line remains identifiable even when colors are converted through CTB or STB plot settings.

Consistent symbols

A company-approved symbol can repeat at controlled intervals.

Better multidisciplinary coordination

Different networks can remain distinguishable when they cross or run close together.

Limitations

More difficult syntax

Complex definitions include multiple parameters and dependencies.

External resources may be required

Text styles, fonts and SHX files must be managed correctly.

File exchange is more sensitive

A recipient may not have access to the required support files.

Scale problems are more visible

Text and symbols may become too large, too small or too closely spaced.

More testing is required

Complex linetypes should be checked on different objects, drawing units, viewport scales and CAD platforms.

How Linetype Scale Affects Simple and Complex Patterns

The size of a linetype pattern is not controlled by the LIN definition alone.

It is influenced by:

  • LTSCALE
  • CELTSCALE
  • The object’s Linetype Scale property
  • MSLTSCALE
  • PSLTSCALE
  • The current annotation scale stored in CANNOSCALE

Global Scale with LTSCALE

The LTSCALE system variable applies a global scale factor to linetypes in the drawing.

A larger value creates longer dashes and larger spaces.

For example:

  • LTSCALE = 0.5 produces a smaller pattern.
  • LTSCALE = 1 uses the standard scale.
  • LTSCALE = 10 enlarges the pattern.

The appropriate value depends on the drawing units, plotting method and CAD standard.

Current Object Scale with CELTSCALE

The CELTSCALE system variable sets the linetype scale applied to newly created objects.

It does not automatically modify existing geometry.

For consistent drawings, a value of 1.0 is commonly retained unless a project standard requires otherwise.

Individual Object Linetype Scale

Each compatible object can have its own Linetype Scale property.

The final pattern results from the combined effect of:

  • The LIN definition
  • LTSCALE
  • The individual object scale
  • Model-space and paper-space scaling settings

Using many different object-scale overrides can make a drawing difficult to maintain. In most standardized workflows, individual objects remain at 1.0.

Model-Space Scaling with MSLTSCALE

When MSLTSCALE is enabled, model-space linetypes are scaled according to the current annotation scale.

The current annotation scale is controlled through CANNOSCALE.

For example, changing the annotation scale from 1:1 to 1:50 can affect the displayed linetype pattern when MSLTSCALE = 1.

This behavior helps preview linetypes in model space at a size related to the intended plotted scale.

Paper-Space Scaling with PSLTSCALE

The PSLTSCALE system variable controls the appearance of non-continuous linetypes inside layout viewports.

When enabled, it helps display linetypes at a consistent paper-space size across viewports that use different scales.

A drawing containing several viewport scales should always be regenerated and checked in the final layout.

Why Complex Linetypes Are More Sensitive to Scale

An ordinary dashed pattern may remain understandable across a wide scale range.

A complex linetype is less tolerant because the embedded text or shape must remain readable.

Incorrect scaling may cause:

  • Overlapping labels
  • Oversized symbols
  • Tiny characters
  • Excessive gaps
  • Missing repetitions
  • Poor results on short objects
  • Unreadable patterns on tight curves

Complex linetypes should be designed and tested for a defined range of drawing and plotting scales.

Linetype Behavior on Different Object Types

Lines

A line contains one continuous segment, so the linetype normally repeats predictably.

The direction of the line can still affect text orientation when R= is used. The U= upright option is preferable when labels must remain readable in both directions.

Polylines

A polyline may contain several segments and vertices.

Its Linetype Generation property determines whether the pattern:

  • Continues across vertices
  • Restarts on each segment

Continuous generation can produce a more regular appearance along utility routes and long alignments.

Arcs, Circles and Curved Polylines

Complex linetypes can follow curved objects, but the result depends on:

  • The curve radius
  • The pattern length
  • The text scale
  • The chosen rotation option
  • The object direction

Text and shapes may overlap on very small radii.

Short Objects

A short object may not contain enough length to display a complete pattern.

It may appear:

  • Continuous
  • As one dash
  • Without text
  • Without its shape
  • With an incomplete repetition

Possible corrections include:

  • Reducing the linetype scale
  • Lengthening the object
  • Shortening the pattern
  • Using a simpler definition
  • Adding a separate annotation

Multilines

A multiline created with MLINE is controlled by a multiline style.

The components, offsets, colors and linetypes are configured through MLSTYLE and stored in the drawing. Multiline styles can also be saved and loaded through MLN files.

A multiline should therefore not be treated as one ordinary object receiving a single linetype definition.

Hatches

Hatches use PAT pattern definitions, not LIN definitions.

A hatch pattern and a linetype are different systems:

  • LIN files define patterns along linear objects.
  • PAT files define repeated patterns across an enclosed area.

The Linetype property of a hatch does not replace its hatch pattern.

Compatibility Across CAD Software

AutoCAD and AutoCAD LT

AutoCAD supports:

  • Simple custom linetypes
  • Text-based complex linetypes
  • Shape-based complex linetypes
  • Custom LIN files
  • SHX resources

AutoCAD LT can load and use many custom linetypes, although some advanced creation, compilation or automation workflows may differ from full AutoCAD.

Capabilities should be checked for the exact version in use.

AutoCAD for Mac

AutoCAD for Mac can use custom LIN definitions and supported complex linetypes.

Important considerations include:

  • Correct support folders
  • Available SHX files
  • Compatible fonts
  • Exact file names
  • Stable file locations

Custom resources should be stored in an approved support folder rather than in a temporary download directory.

BricsCAD, ZWCAD, GstarCAD and Other DWG-Compatible Applications

Many DWG-compatible programs support standard LIN syntax.

Simple definitions normally provide the best interoperability.

Complex definitions should be tested for:

  • Text orientation
  • Font substitution
  • SHX support
  • Shape rendering
  • Curve behavior
  • Model-space scaling
  • Layout viewport scaling

A linetype that displays correctly in one application may require adjustments in another.

How to Choose Between a Simple and Complex Linetype

Choose a Simple Linetype When

Use a simple linetype when:

  • A dash pattern provides enough information.
  • Maximum compatibility is required.
  • The drawing will be exchanged with many external users.
  • No supporting files should be distributed.
  • Easy maintenance is a priority.
  • The object represents hidden, center or construction geometry.
  • The object already has a clear layer name or separate annotation.

Choose a Complex Linetype When

Use a complex linetype when:

  • A system must be identified directly on the line.
  • Several networks use similar geometry.
  • A repeated symbol is part of the drafting standard.
  • The drawing must remain readable without color.
  • Manual labels would be difficult to maintain.
  • Supporting resources can be managed centrally.
  • The pattern can be tested at all required scales.

Decision Table

Requirement Recommended Linetype
Maximum DWG compatibility Simple
Hidden or center geometry Simple
Repeated system label Complex text
Repeated technical symbol Complex shape
No external resources Simple
Strong visual identification Complex
Easy editing and maintenance Simple
External consultant workflow Usually simple
Controlled company environment Simple or complex
Monochrome network drawings Complex
Small-radius curves Usually simple
Standard utility plans Complex

How to Create a Custom Simple Linetype

Write the Definition

Create or open a plain-text LIN file.

Add the header:

*CUSTOM_DASH,Custom dashed line

On the next line, add the pattern:

A,.75,-.25

The complete definition is:

*CUSTOM_DASH,Custom dashed line
A,.75,-.25

Save the file with the .lin extension.

Do not use a rich-text editor that inserts hidden formatting.

Load and Test the Linetype

In the CAD application:

  1. Open the linetype manager.
  2. Select Load.
  3. Browse to the custom LIN file.
  4. Select the required definition.
  5. Assign it to a test layer or object.
  6. Regenerate the drawing.
  7. Check the result at several scales.

Test the pattern on objects with different lengths and directions.

Adjust the Pattern

To modify the appearance:

  • Increase positive values for longer dashes.
  • Increase negative values for larger spaces.
  • Add zero values for dots.
  • Reduce the values for a denser pattern.
  • Confirm that the definition suits the drawing units.
  • Reload the definition after editing the LIN file.

How to Create a Custom Complex Linetype

Choose Between Text and Shapes

Use text when the pattern needs:

  • A system name
  • An abbreviation
  • A material code
  • A service identifier

Use a shape when the pattern needs:

  • A graphical symbol
  • A fence marker
  • A railway symbol
  • A directional marker
  • A specialized company symbol

Text-based definitions are normally easier to maintain because they may require fewer external resources.

Create the Text Style First

Before loading a text-based complex linetype:

  1. Create the required text style.
  2. Assign an approved font.
  3. Set the style height to 0.0.
  4. Save the drawing or template.
  5. Load the complex linetype.

This prevents many text-size and loading problems.

Define Scale, Rotation and Offsets

Example:

*UTILITY_LINE,Utility line ---- UTIL ----
A,.50,-.15,["UTIL",STANDARD,S=.10,U=0.0,X=-.05,Y=-.05],-.20

Adjust:

  • S= for character size
  • U= for upright text
  • R= for relative rotation
  • A= for absolute rotation
  • X= for horizontal placement
  • Y= for vertical placement

Test the Definition

Test the linetype on:

  • Horizontal lines
  • Vertical lines
  • Diagonal lines
  • Lines drawn in opposite directions
  • Polylines
  • Arcs
  • Circles
  • Short segments
  • Model-space views
  • Layout viewports

Package the Supporting Files

A complete custom linetype package may include:

  • The LIN file
  • Required SHX files
  • Approved fonts
  • A sample DWG
  • Installation instructions
  • Recommended scale values
  • Software compatibility notes
  • Version information
  • A preview drawing or PDF

Common Linetype Definition Errors

Invalid Header and Pattern Formatting

The header and the pattern must appear on two separate lines.

Incorrect:

*DASHED,Dashed lineA,.50,-.25

Correct:

*DASHED,Dashed line
A,.50,-.25

Other common syntax errors include:

  • Missing commas
  • Missing brackets
  • Incorrect quotation marks
  • Invalid parameter names
  • Empty values
  • Accidental line breaks
  • Incorrect file extensions
  • Rich-text formatting

Missing Text Style

A complex text linetype may fail when the referenced text style does not exist.

Possible symptoms include:

  • Missing text
  • Font substitution
  • Incorrect character size
  • Loading errors
  • Unexpected spacing

Create the required style before loading the linetype.

Fixed Text-Style Height

A text style with a fixed height other than zero can produce:

  • Oversized text
  • Very small text
  • Inconsistent scaling
  • Overlapping characters

Set the style height to 0.0 and control the size with the LIN definition’s S= value.

Missing SHX File

A shape-based linetype may fail when:

  • The SHX file is absent.
  • The file is outside the support path.
  • The file name is incorrect.
  • The shape name does not exist.
  • A different SHX file uses the same name.

Confirm that the correct file is installed in an accessible support folder.

Incorrect Scale or Offsets

Poor parameter values can create:

  • Text that is too large
  • Symbols that are too small
  • Overlapping pattern elements
  • Excessive blank spaces
  • Text positioned above or below the line
  • Shapes separated from the object

Adjust one parameter at a time and reload the definition after each change.

Text Displayed Upside Down or Reversed

This problem usually occurs when R= is used and the object changes direction.

Use:

U=0.0

instead of:

R=0.0

when the text must remain upright.

Also test:

  • Objects drawn from left to right
  • Objects drawn from right to left
  • Upward and downward lines
  • Closed polylines
  • Curved segments

Best Practices for CAD Linetype Standards

Use Clear Names

Use descriptive names such as:

  • CIVIL_WATER_EXISTING
  • CIVIL_WATER_PROPOSED
  • MECH_COMPRESSED_AIR
  • ELEC_FIRE_ALARM
  • ARCH_DEMOLITION
  • SITE_FENCE

Avoid vague names such as:

  • LINE1
  • DASH2
  • TEST
  • NEWTYPE

A prefix can identify the discipline, company or project standard.

Keep Definitions as Simple as Possible

Do not use text or shapes when an ordinary dashed pattern is sufficient.

Each dependency adds:

  • Installation work
  • Maintenance requirements
  • Compatibility risks
  • Troubleshooting time

Use a complex linetype only when it provides a clear drafting or coordination benefit.

Assign Linetypes ByLayer

In most standardized drawings, objects should use ByLayer for their linetype property.

This allows the layer standard to control the appearance consistently.

Direct object overrides should be limited to documented exceptions.

Standardize Text Styles and SHX Resources

For complex definitions:

  • Use approved text styles.
  • Set linetype text styles to a height of 0.0.
  • Use controlled fonts.
  • Store SHX files in a central location.
  • Avoid duplicate file names.
  • Document installation procedures.
  • Maintain version information.

Test Before Deployment

Test custom linetypes with:

  • Metric drawings
  • Imperial drawings
  • Several LTSCALE values
  • Several annotation scales
  • Lines and polylines
  • Arcs and circles
  • Short and long objects
  • Model space
  • Paper space
  • Different viewport scales
  • CTB and STB plotting
  • PDF export
  • All supported CAD applications

Include Approved Linetypes in Templates

Approved linetypes can be loaded into company DWT templates and assigned to standard layers.

This provides:

  • Consistent names
  • Correct layer assignments
  • Faster drawing setup
  • Fewer missing definitions
  • Better project coordination

Required LIN, SHX and font files should also be included in the CAD deployment system.

Frequently Asked Questions

What is the main difference between simple and complex CAD linetypes?

A simple linetype contains only dashes, spaces and dots. A complex linetype also contains text or graphical shapes.

Can a simple linetype contain text?

No. A linetype containing embedded text is classified as a complex linetype.

Can a complex linetype work without an SHX shape file?

A text-based complex linetype does not require a custom shape file, but it does require a valid text style and an available font.

A shape-based complex linetype requires access to the referenced SHX shape file.

What does the initial A mean in a LIN pattern?

The initial A specifies the standard alignment mode used to align the pattern along the object.

What is the difference between U=, R= and A=?

  • U= keeps text or shapes upright and readable.
  • R= rotates them relative to the direction of the object.
  • A= maintains an absolute angle relative to the drawing coordinate system.

Why does a linetype appear continuous?

The object may be too short, the pattern scale may be unsuitable or the drawing may need to be regenerated.

Check the scale settings described in the section covering LTSCALE, CELTSCALE, MSLTSCALE and PSLTSCALE.

Why is text missing from a complex linetype?

Possible causes include:

  • A missing text style
  • A missing font
  • An incorrect scale
  • A fixed text-style height
  • An object that is too short
  • Invalid LIN syntax

Can complex linetypes follow curves?

Yes. They can follow arcs, circles and curved polylines, but text and shapes may become difficult to read on small-radius curves.

Why is the linetype text upside down?

The definition may use relative rotation with R=.

Use U=0.0 when the characters must remain upright regardless of object direction.

Can the same LIN file be used in metric and imperial drawings?

It can be loaded in both unit systems, but one pattern size may not suit both.

Separate metric and imperial definitions usually provide better control.

What is the difference between a text style and an SHX shape?

A text style controls the appearance of text characters.

An SHX shape is a compiled graphical definition used as a symbol rather than ordinary text.

Should custom linetypes be assigned ByLayer?

Yes, in most standardized CAD workflows. ByLayer assignments make drawings easier to manage and keep object appearance consistent.

Conclusion: Which CAD Linetype Should You Use?

The main difference between simple and complex CAD linetypes lies in the elements contained in their repeating patterns.

A simple linetype uses:

  • Dashes
  • Spaces
  • Dots

It is easy to create, easy to share and well suited to hidden lines, centerlines, construction geometry and general drafting conventions.

A complex linetype adds:

  • Repeated text
  • SHX shapes
  • Scale parameters
  • Rotation controls
  • Positioning offsets

It is suitable for utility networks, pipelines, fences and other technical objects that need to display an identifier or symbol directly along their geometry.

Use a simple linetype when portability, compatibility and maintenance are the main priorities.

Use a complex linetype when the line must carry additional information and the required text styles, fonts and shape files can be managed correctly.

Before deploying either type, test the definition with the intended drawing units, linetype scales, annotation scales, object types, viewport scales and CAD applications.

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