How to Create Custom Linetypes (.LIN) with Embedded Text or Shapes (MKLTYPE & MKSHAPE)
Complete guide to authoring custom utility and civil linetypes (--GAS--, --RW--, fence lines) in GstarCAD using ASCII .lin definitions or Express Tools MKLTYPE.
Define custom text linetypes directly in gcad.lin (or acad.lin) using the syntax A,dash,-gap,["TEXT",STYLE,S=scale,U=0,X=offset,Y=offset],-gap or generate them graphically in 10 seconds using the Express Tool MKLTYPE.
1. Root Cause & DWG Database Symptom Analysis
Civil, utility, and P&ID drawings rely heavily on complex linetypes embedding inline text letters (--- GAS ---, --- FIBER OPTIC ---, --- STORM ---) or geometric shapes (fences, retaining walls, railroad tracks). Understanding how GstarCAD parses .lin descriptors prevents upside-down text and missing `.shx` shape errors.
2. Step-by-Step Resolution in GstarCAD & AutoCAD
Step 1: Write a Portable ASCII Text Linetype Definition (.LIN)
Every `.lin` definition consists of two lines: a header line starting with *LINETYPE_NAME,Description and a pattern line starting with alignment code A. Positive numbers draw dashes, negative numbers lift the pen (gaps), and bracketed descriptors ["GAS",STANDARD,S=2.5,U=0.0,X=-2.5,Y=-1.25] embed inline text.
Step 2: Use U=0.0 (Upright Rotation) So Text Never Plots Upside Down
In older drawings using R=0.0 (Relative rotation), drawing a utility line from right-to-left caused the embedded text `GAS` to flip upside down! Replacing R=0.0 with U=0.0 (Upright) forces GstarCAD to keep the text right-reading regardless of polyline vertex direction.
Step 3: Graphical Creation via Express Tools MKSHAPE & MKLTYPE
Prefer not to write ASCII code? Draw your repeating segment on screen, run MKSHAPE (if embedding custom geometry) followed by MKLTYPE, pick a filename, name the linetype, and select the start/end points—GstarCAD compiles and loads the `.lin` file automatically.
3. System Variables & Command Diagnostic Table
| Variable / Command | Default / Target Value | Diagnostic Function & Fix Behavior |
|---|---|---|
U=0.0 (Upright) |
Modern Text Orientation | Keeps embedded linetype text readable even on right-to-left lines |
S=2.5 (Scale) |
Text Height Multiplier | Multiplies by LTSCALE (or Text Style height if fixed) |
X / Y Offsets |
Centering Shifts | Centers the text string horizontally inside the negative pen-up gap |
MKLTYPE / MKSHAPE |
Express Commands | Compiles graphical geometry into .shp/.shx and .lin files visually |
4. One-Click AutoLISP Fix Script (AutoLISP Programmatic Custom Utility Linetype Loader)
(defun c:MAKE-GAS-LTYPE ( / fn fp)
(setq fn (strcat (getvar "TEMPPREFIX") "custom_util.lin")
fp (open fn "w"))
(write-line "*UTIL_GAS,Gas pipeline --- GAS --- GAS ---" fp)
(write-line "A,25.0,-5.0,["GAS",STANDARD,S=2.5,U=0.0,X=-2.5,Y=-1.25],-8.0" fp)
(close fp)
(if (not (tblsearch "LTYPE" "UTIL_GAS"))
(command "_.-LINETYPE" "_L" "UTIL_GAS" fn ""))
(princ "\n[Linetype Engine] Loaded upright 'UTIL_GAS' linetype.")
(princ)
)Enterprise AC1032 Database Internals & Cross-Version Diagnostics
In multi-office engineering environments operating across GstarCAD 2027, GstarCAD Mechanical, GstarCAD Architecture, and legacy AutoCAD (2018–2027) seats, mastering How to Create Custom Linetypes (.LIN) with Embedded Text or Shapes (MKLTYPE & MKSHAPE) requires understanding how the underlying AC1032 DWG binary database serializes entity handles, symbol table records, and Named Object Dictionary (NOD) pointers.
1. DWG Header & Registry Persistence Scope
Variables and object properties fall into three persistence scopes: Drawing-Saved (DXF Header) variables that travel with the .dwg file to subcontractors, Registry-Saved (Profile .arg) settings that persist per Windows workstation user, and Session-Volatile states that reset on every launch unless locked inside acaddoc.lsp. Always verify persistence scope via SYSVDLG before issuing sheets to an ISO 19650 Common Data Environment (CDE).
2. Multi-Core Regeneration & Memory Hygiene
When processing large civil corridors, dense plant P&IDs, or 50-sheet architectural Xref trees, unpurged Registered Application IDs (REGAPP), orphaned DGN stroke dictionaries, and redundant annotation scales degrade spatial index (INDEXCTL = 3) lookup speed. Executing a pre-submittal AUDIT, command-line -PURGE → Regapps, and OVERKILL pass keeps file open times under 2 seconds on GstarCAD's multi-threaded graphics kernel.
3. Hybrid AutoCAD + GstarCAD Team Coexistence
Because GstarCAD reads and writes native AC1032 binary records without intermediate import/export translation, dynamic block grips, associative hatches, XData payloads (DXF groups 1000–1071), Paper Space viewport layer overrides (VPLAYER), and X.509 digital signatures round-trip losslessly between AutoCAD and GstarCAD seats on shared SMB/BIM cloud folders.
Production Field Verification Protocol (ISO 9001 / ISO 19650 Gate)
- Baseline Template Audit: Confirm that the active drawing inherits layer naming, linetype scales (
PSLTSCALE = 1,MSLTSCALE = 1,LTSCALE = 1.0), and dimension styles from the enterprise.dwt/.dwsstandards file viaCHECKSTANDARDS. - Coordinate & Unit Integrity: Run
-DWGUNITSor checkINSUNITS,LUNITS, andMEASUREMENTto guarantee 1:1 metric (`mm`/`m`) or imperial (`in`/`ft`) block and Xref insertion scaling, withOSNAPZ = 1preventing unintended 3D elevation drift. - Submittal Packaging & Mobile Review: Lock all Paper Space viewports (`DisplayLocked = Yes`), bind or relative-path all external references via
ETRANSMIT, and verify final plotted PDF/A lineweights (`ISO full bleed`) alongside DWG FastView mobile cloud markup links.
Related Engineering Guides, Courses & Troubleshooting FAQs
Continue building your CAD engineering mastery with these related GstarCAD Academy technical references:
- [Engineering Guide] ASME Y14.5-2018 GD&T 14 Geometric Characteristic Symbols & Modifiers Handbook
- [Engineering Guide] Course 23: 3D Surface Modeling — Loft, Sweep, Continuity (G0/G1/G2) & NURBS Patch Workflows
- [Engineering Guide] Course 29: Welding Symbols (AMWELDSYM), Surface Texture (AMSURFSYM) & GD&T Feature Control Frames
- [Troubleshooting FAQ] How to Export Revit Views to Clean, Standard-Layered DWG Files for GstarCAD
- [Troubleshooting FAQ] How to Fix 3D Boolean UNION, SUBTRACT & INTERSECT 'Modeling Operation Error' in CAD
- [Troubleshooting FAQ] How to Fix FILLET and CHAMFER Not Working ('Lines Are Non-Coplanar' or 'Radius Too Large')
- [Skill Certification] Test Your Mastery on the 850-Question GstarCAD Engineering Certification Engine →
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