Tutorials

How to add hatch pattern in AutoCAD LT 2021? (Solved)

Many users want a clear, step‑by‑step guide for adding Hatch patterns in AutoCAD LT 2021 — how to use built‑in patterns, how to add custom patterns (.pat), and how to fix common problems. This guide gives a concise quick answer and a full, beginner‑friendly tutorial with alternatives, troubleshooting, and practical tips.

Quick answer

To add a Hatch pattern in AutoCAD LT 2021:

  1. Start the HATCH command (type HATCH or click Hatch on the Draw panel).
  2. Choose a pattern from the Hatch Creation ribbon or Properties palette.
  3. Select the boundary (use Pick Points or Select Boundary Objects).
  4. Set Scale, Angle, and Associative as needed, then click OK or press Enter.

To use a custom pattern (.pat), put the .pat file in a folder listed in AutoCAD’s Support File Search Path (Options > Files > Support File Search Path), restart AutoCAD, then the pattern will appear in the Hatch pattern list.

Full step‑by‑step tutorial

Step 1 — Open the Hatch tool

  • Type HATCH in the command line or click the Hatch button on the Draw panel (Home tab). The Hatch Creation tab (ribbon) opens.

Step 2 — Choose a hatch pattern

  • In the Hatch Creation ribbon, open the Pattern dropdown.
  • Select a built‑in pattern (ANSI, ISO, User Defined, etc.). The preview shows the chosen pattern.
  • Set Pattern Type (Predefined, Custom) if needed.
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Step 3 — Set scale and angle

  • Enter a Scale value to control pattern density (smaller scale = denser pattern).
  • Enter an Angle to rotate the pattern.
  • Optionally enable Annotative if you want the hatch to scale automatically for viewports.

Step 4 — Select boundary

  • Choose Pick Points to click inside a closed area.
  • Or use Select Boundary Objects to pick polylines, circles, or regions that form the closed boundary.
  • If AutoCAD reports an open area, use the Boundary or Join tools to close gaps before hatching.

Step 5 — Preview and create

  • Use the preview to confirm filling.
  • Click OK (or press Enter) to create the hatch. If Associative is on, the hatch will update if the boundary is edited.

How to add a custom hatch pattern (.pat) in AutoCAD LT 2021

  1. Obtain or create a .pat file (text file containing pattern definitions).
  2. Open AutoCAD > Application menu > Options (or type OPTIONS).
  3. Go to the Files tab > expand Support File Search Path.
  4. Click Add, then Browse to the folder where you put the .pat file. You can create a dedicated folder like C:\AutoCAD\Support\Hatches.
  5. Click OK to save changes and restart AutoCAD LT.
  6. The new pattern should now appear in the Hatch pattern list under User Defined (or search by name in the Pattern dropdown).

Alternative import method:

  • If you have a DWG that already contains the custom hatch, open that DWG, open DesignCenter (Ctrl+2), find the hatch pattern/definition and drag it into your current drawing. (DesignCenter is a fast way to copy hatch definitions without editing support paths.)

Detailed options and important settings

  • Associative: When checked, the hatch remains linked to its boundary so editing the boundary updates the hatch automatically. Disable if you need a static hatch.
  • Annotative: Useful for hatches that must appear at the correct scale across multiple viewports. Be careful: annotative hatches require correct annotation scales.
  • Set Origin: Use the Set Origin tool to align a hatch pattern’s origin point so repetitive patterns align across adjacent hatches.
  • Hatch Scale vs Drawing Units: Hatch scale is affected by current drawing units. If a pattern looks huge or tiny, check units and adjust the hatch scale accordingly.
  • Island detection: Control whether holes inside boundaries are treated as islands (excluded) or as islands to be hatched via the Hatch Creation ribbon > Boundaries options.
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Alternative methods and shortcuts

  • Use Pick Points for fast fills of simple closed areas.
  • Use Select Boundary Objects when the boundary is already drawn as polylines, circles, regions, or closed splines.
  • Use the BOUNDARY command to create a closed polyline from a region with small gaps — then hatch the resulting polyline.
  • Use DesignCenter (Ctrl+2) to copy hatch patterns or sample hatch from other drawings.
  • For patterned fills that are native to full AutoCAD features not available in LT, create the hatch in full AutoCAD and then import the filled area as a block or reference into LT.

Common errors and fixes

  • Problem: “Hatch not filling” or empty preview.

    • Fixes:
      • Ensure the area is a closed boundary. Use PEDIT > Join or BOUNDARY to close gaps.
      • Zoom in to find tiny gaps; join or draw closing segments.
      • If using Pick Points, confirm you clicked inside the region that AutoCAD recognizes as closed.

  • Problem: Pattern looks too large or too small.

    • Fixes:
      • Adjust the Scale value in the Hatch properties.
      • Check drawing Units (UNITS command) — pattern scale depends on unit system.
      • If using an imported .pat designed for different units, try multiplying/dividing the scale.

  • Problem: Custom .pat not listed.

    • Fixes:
      • Verify the .pat file is in a folder listed under Support File Search Path and restart AutoCAD.
      • Make sure the .pat file syntax is correct (no corrupted lines).
      • Confirm the file extension is .pat and not .txt.

  • Problem: Hatch displays incorrectly in paper space or viewport.

    • Fixes:
      • Use Annotative hatches or adjust the hatch scale to match the viewport scale.
      • Regenerate the drawing (REGEN) or toggle VPFreeze settings.
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Practical tips and best practices

  • Keep a dedicated folder for custom .PAT files and add it to the Support File Search Path for easy management and portability.
  • Use Set Origin to align pattern origins across multiple hatched areas for a continuous look.
  • Make hatches associative when you expect boundary edits; turn it off when you need a stable fill.
  • Create sample hatch blocks with common scales for quick insertion.
  • Save frequently used hatch configurations as Tool Palettes or templates to speed repetitive tasks.
  • When collaborating, share the custom .pat files with your team and agree on naming/scale conventions to avoid mismatches.

FAQ

How do I make a hatch pattern tile seamlessly across multiple adjacent areas?

Ensure each hatch uses the same Scale and Origin. Use the Set Origin tool to pick the same reference point for each hatch so the pattern lines up seamlessly.

Can I edit a hatch pattern after creation?

Yes. Select the hatch and use the Properties palette or the Hatch Creation ribbon to change Pattern, Scale, Angle, and Associativity. For more structural changes, you may need to recreate the hatch after modifying the boundary.

Will custom .pat files work on other computers?

Only if the other computer has the same .pat file in a folder listed in its Support File Search Path. Share the .pat file and advise team members to add the folder to their Options > Files > Support File Search Path.

Why does my hatch disappear in a viewport?

Usually because of scale/annotative settings. Make the hatch annotative or adjust its scale to match the viewport scale. Try REGEN or REGENALL if it still doesn’t appear.

How do I close small gaps that prevent hatching?

Use PEDIT > Join, draw a small closing segment, or use Boundary to create a closed polyline from the area. Zoom in and inspect intersections carefully; sometimes snapping settings can help close them precisely.

Are there limitations in AutoCAD LT 2021 for hatching compared to full AutoCAD?

AutoCAD LT supports hatch creation, custom .pat files, and DesignCenter. It does not support AutoLISP or some third‑party automation available in full AutoCAD, but the core hatch functionality (patterns, scale, origin, associativity) is available.

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