Guide

AutoCAD Linetype : A pattern used to create dashed lines or other repetitive graphical patterns

If you’re looking for a complete, beginner-friendly guide to linetype usage in AutoCAD, this article explains what a linetype is, why and when to use it, how to load and edit linetypes, step‑by‑step workflows, alternative methods, common errors and fixes, practical tips for plotting, and a helpful FAQ.

What is the linetype?

definition

A linetype in AutoCAD is a repeating graphical pattern used to draw lines that are not continuous — for example, dashed, dotted, centerlines, or patterns that include text or symbols. Linetypes control how a line appears on screen and on print, independent of its color or lineweight.

Common built-in linetypes

AutoCAD ships with many standard linetypes such as CONTINUOUS, HIDDEN, CENTER, PHANTOM, DOT, and DASHDOT. These are stored in .lin definition files and loaded into your drawing when needed.

Purpose and benefits of using linetype

  • Convey technical meaning (e.g., hidden edges, centerlines, section lines).
  • Improve readability and standards compliance in engineering and architectural drawings.
  • Allow different symbolic representations without changing geometry.
  • Facilitate plotting and communication of construction or manufacturing intent.
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Why, how and when to use linetypes

Why use them

Use linetypes to represent different types of features consistently (hidden objects, centers, property boundaries, etc.) and to comply with company or industry drafting standards.

When to use them

  • When a line must indicate something beyond just a geometry (hidden, center, break lines).
  • On construction documents and detail drawings where visual distinction is essential.
  • For CAD standards enforcement: assign specific linetypes per layer (e.g., all centerlines on layer “CENTER” use CENTER linetype).

How to use them (overview)

  • Load the desired linetype definitions into the drawing.
  • Assign the linetype to objects directly or via layers.
  • Scale the linetype so the dash and gap sizes are appropriate at the drawing/plot scale.

Step-by-step: Load and apply linetypes (GUI and command line)

Method A — Using the Linetype Manager (GUI)

  1. Type LINETYPE (or use Format > Linetype) and press Enter to open the Linetype Manager dialog.
  2. Click Load.
  3. Choose a linetype from the list or click File to load another .lin file.
  4. Select the linetype and click OK to load it into your drawing.
  5. Assign the linetype to a layer via layer properties Manager or to selected objects using the Properties palette.

Method B — Command-line workflow

  1. Type LINETYPE and press Enter, or type -LINETYPE for command-line controls.
  2. Use Load to load definitions, or Set to assign a loaded linetype to selected objects.
  3. Use LTSCALE, PSLTSCALE, and MSLTSCALE variables (see section below) to adjust display.

Linetype scale: LTSCALE, PSLTSCALE, MSLTSCALE

  • LTSCALE — Global linetype scale affecting all linetypes in the drawing. Increase or decrease to scale dash lengths and gaps.
  • PSLTSCALE — Controls linetype scaling for paper space viewports. Set to 1 to scale linetypes in viewports according to viewport scale (recommended for plotting). Set to 0 for uniform model-space display.
  • MSLTSCALE — When set to 1, AutoCAD scales linetypes in Model space according to the annotation scale. Useful when using annotation scales and multiple drawing scales.

Common workflow for plotting:

  • Set LTSCALE to the scale factor you want (often match model-to-paper scale).
  • Set PSLTSCALE = 1 so viewports display linetypes correctly at plot scale.
  • Use REGEN (or REGENALL) after changes.
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How to create or edit a custom linetype

Create a .lin file (basic approach)

  1. Open a text editor (Notepad).

  2. Add a new linetype entry using this basic structure:
    Example line in .lin

    • CENTER, Centerline ____
      A, 0.5, -0.25, 0.25
    • First line: starts with an asterisk and contains the name and description.
    • Second line: pattern definition with numbers for dash/gap lengths; letters or quoted text for embedded text/symbols (requires SHX fonts).

  3. Save the file with a .lin extension.

  4. In AutoCAD, use LINETYPE > Load > File to load the new .lin.

Edit an existing linetype

  • Edit the corresponding .lin file (best practice: work on a copy).
  • Reload the linetype in the drawing (unload and reload via LINETYPE dialog or restart AutoCAD).
  • For simple adjustments, change LTSCALE or layer/object scale rather than editing the .lin file.

Note: Linetype definitions assume the same Measurement units as the drawing. If your drawing units differ (metric vs imperial), adjust pattern values accordingly.

Assigning linetypes to layers and objects

  • Best practice: assign linetypes to layers so that all objects on that layer share consistent visual style.
  • Use the Layer Properties Manager:
    • Click the linetype cell for a layer.
    • Choose a loaded linetype.
    • All objects on that layer will adopt the linetype (unless an object’s linetype has been set explicitly).
  • To change a single object’s linetype: select the object and modify its Linetype property in the Properties palette.

Alternative methods and shortcuts

  • Use -LINETYPE (command-line) for scripting and automation.
  • drag and drop a .lin file into AutoCAD to open the Linetype dialog quickly in some versions.
  • Use Layer States to store preferred linetypes per layer for different drawing phases.
  • Use DesignCenter (type ADCENTER) to copy layers and linetypes from other drawings.

Common errors and fixes

  • Linetype appears continuous (no dashes):

    • Fix: Check LTSCALE (increase/decrease), set PSLTSCALE = 1 for viewports, try REGEN.
    • Ensure the linetype is loaded into the drawing.
    • Confirm the linetype’s dash lengths are not too small relative to the drawing unit scale.

  • Linetype pattern repeats at unexpected points:

    • Explanation: Linetype patterns are based on the object start point. Breaks or grips can restart the pattern.
    • Fix: Use JOIN to combine segments, or redraw as a single polyline if continuous appearance is needed.

  • Custom linetype text does not display:

    • Fix: Ensure the text uses an SHX font available in AutoCAD and referenced correctly in the .lin file.
    • Place the .lin and font files in a folder listed in the Support File Search Path.

  • Different appearance in model space vs paper space:

    • Fix: Use PSLTSCALE = 1 and adjust LTSCALE appropriately. Consider MSLTSCALE if using annotation scales.

  • Plotting shows different linetype from display:

    • Fix: Use REGEN and preview the plot. Check plot scale and LTSCALE. Confirm printer/plotter driver interprets linetype correctly.
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Practical tips and best practices

  • Assign linetypes to layers (not to individual objects) for consistent drafting standards.
  • Keep a central .lin library for your office CAD standards and store it on a shared network path.
  • Use simple SHX fonts for embedded text in linetypes to ensure portability.
  • When working across metric/imperial files, be mindful of units: dash lengths are in drawing units.
  • For plotting, test a viewport with PSLTSCALE = 1, adjust LTSCALE, and preview before plotting the final sheet.
  • Use REGEN after changing linetype settings to refresh display.
  • Avoid extremely small dash sizes; they may disappear at certain scales or on some printers.

Examples and quick recipes

Load and assign a linetype to a layer

  1. Type LINETYPE > Load > choose HIDDEN > OK.
  2. Open Layer Properties Manager, select the layer, click linetype cell, choose HIDDEN.

Make dashed lines visible (common fix)

  1. Type LTSCALE and set an appropriate value (e.g., 2 or 0.5 depending on scale).
  2. Type PSLTSCALE = 1 if in paper space viewports.
  3. Type REGENALL.

Create a simple dashed linetype for metric drawings

  1. Edit a .lin: pattern numbers use metric units (e.g., 1.0, -0.5, 0.5).
  2. Load the .lin via LINETYPE > Load.

FAQ — How do I make a custom linetype with text in it?

You need to create a .lin file and reference an SHX font for text entries. Place the text in quotes in the pattern definition and ensure the SHX file is available in AutoCAD’s support path. Load the .lin file using LINETYPE dialog.

FAQ — Why do my linetypes look different in viewports than in model space?

Set PSLTSCALE = 1 so that linetypes are scaled in viewports according to the viewport scale. Also verify LTSCALE and use REGEN after changes.

FAQ — What is the difference between linetype and lineweight?

Linetype defines the pattern (dashes, dots); lineweight controls the thickness of the printed line. Both can be combined to convey meaning and should be set according to drafting standards.

FAQ — How can I apply a linetype only to one object and not the entire layer?

Select the object, open the Properties palette, and set its Linetype property. This overrides the layer linetype for that object.

FAQ — My custom linetype is not visible after loading — what should I check?

Confirm the .lin file syntax is correct, that any referenced SHX fonts exist, that the linetype has been loaded into the current drawing, and adjust LTSCALE and PSLTSCALE as needed. Use REGEN to refresh.

FAQ — How do I make dashed lines plot correctly at different scales?

Use PSLTSCALE = 1; set LTSCALE to your drawing-to-plot scale (or a value that produces acceptable dash sizes); preview and adjust until plot preview matches expectations.

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