How to Load, Reload, and Update Linetypes in AutoCAD
Loading a linetype and maintaining its source are two different operations. A LIN file is an external library; after a definition is loaded, AutoCAD stores a copy in the current DWG. That distinction explains why editing a source file does not automatically update existing drawings.
This guide covers loading, reloading, assignments, duplicate names, and template deployment. For source-file locations, see Where AutoCAD Stores LIN Files.
Loaded Linetypes vs. Linetypes Stored in LIN Files
The LIN file contains reusable definitions. The DWG linetype table contains the definitions currently available in that drawing. Deleting or moving the source LIN file does not necessarily remove a simple loaded pattern from the DWG, but it prevents reliable reloading and deployment to other drawings. Complex definitions can still require external SHX or font resources.
Load a Linetype with Linetype Manager
Open Linetype Manager
Run LINETYPE and choose Load. The manager shows definitions already stored in the drawing and provides access to a standard or custom LIN library.
Select a Standard or Custom LIN File
Use the file button to choose acad.lin, acadiso.lin, or a managed custom file. Select the library that matches the project’s unit and company standard rather than choosing a similarly named pattern from an unknown source.
Select One or Multiple Definitions
Load only the patterns required by the template or project. Loading hundreds of unused definitions makes lists harder to manage and can create duplicate-name risks.
Load a Linetype from Layer Properties Manager
Open Layer Properties Manager, click a layer’s Linetype value, and choose Load if the required definition is not yet available. After loading, return to the selection dialog and assign it to the layer. This workflow is efficient when the goal is immediately creating or correcting a standard layer.
Load a Linetype with the Command Line
Use the LINETYPE Command
The dialog version is appropriate for interactive work and visual selection. It is also the easiest method for a user who does not know the exact definition name.
Use the -LINETYPE Command
The hyphenated command exposes options at the command line and is suitable for scripts and AutoLISP. Use global command and option prefixes in automation, then verify the definition with the drawing’s linetype table. The batch workflow is detailed in the AutoLISP and scripts article.
Assign the Loaded Linetype
Assign It to a Layer
Assign the definition in Layer Properties Manager and keep objects ByLayer. This is the preferred standards workflow because one layer change updates all compliant objects.
Assign It Directly to an Object
Use direct assignment for testing or a justified exception. Direct values override the layer and are harder to find during audits. Review ByLayer vs. ByBlock vs. Direct Linetype Assignment before using them in blocks or templates.
Make It the Current Linetype
Linetype Manager can make a loaded definition current for new objects. In production drafting, the current object linetype is normally left ByLayer so the current layer controls the result.
Reload an Edited Linetype Definition
Edit the Source LIN File
Work on a backed-up copy, preserve the definition name when the intention is to replace it, and change one value at a time. Validate the syntax before deploying the revision.
Reload the Existing Name
Load the same name from the edited source and accept the replacement prompt where provided. If a product refuses to replace it, use a controlled temporary name or remove dependencies in a test drawing before repeating the operation.
Regenerate the Drawing
Run REGEN or REGENALL. Inspect several existing objects rather than only the Linetype Manager preview, especially when text, shapes, curves, or viewports are involved.
Update Objects Using the Linetype
Existing Layer Assignments
Objects that use a layer assigned to the reloaded name should display the revised stored definition after regeneration. Confirm that the layer has not been overridden in a viewport or Xref host.
Existing Object Assignments
Directly assigned objects also use the drawing-table definition by name. Their individual linetype-scale property can still make them look different from ByLayer objects.
Block and Xref Considerations
Block content can inherit properties at several levels, and Xrefs maintain dependent names and host overrides. Use the block article and the Xref and copying article when reloading appears to affect only some content.
Resolve Duplicate Linetype Names
Same Name and Same Definition
If the code is genuinely identical, standardize the source and document one approved owner. Avoid maintaining redundant copies that can drift apart later.
Same Name and Different Definition
Do not assume the last file selected silently becomes authoritative in every drawing. Rename one definition with a company or client prefix, reload from the approved source, and inspect copied objects before publishing the DWG.
Make Linetypes Available in New Drawings
Add Them to a DWT Template
Load approved definitions into the template and assign them to standard layers. This gives each new drawing a known starting point without relying on manual user loading.
Use a Startup Routine
A startup routine can check and load required names when a drawing opens. It should log missing source files and avoid overwriting a conflicting definition without a governed rule.
Use a Central Company Library
Store source LIN and SHX files in a version-controlled support location. The template and loader should reference the same approved release.
Common Loading and Reloading Errors
| Symptom | Likely cause | Next step |
|---|---|---|
| Name does not appear | Invalid header or wrong LIN file. | Check LIN syntax and the selected source. |
| Bad Definition | Invalid pattern or descriptor. | Use the error guide. |
| Old appearance remains | Definition was not reloaded or drawing not regenerated. | Reload the same name and run REGENALL. |
| Only some objects differ | Object scale, blocks, Xrefs, or overrides. | Trace the property hierarchy. |
| Text or symbol missing | Font, style, or SHX dependency unavailable. | Check support paths and package files. |