Linetype vs. Lineweight vs. Color vs. Plot Style: What Is the Difference?

In AutoCAD and other CAD software, the appearance of an object is controlled by several separate properties. The most important are linetype, lineweight, color, and plot style.

These properties often work together, but they do not perform the same function:

• Linetype controls the pattern of a line.
• Lineweight controls its printed thickness.
• Color controls its on-screen color and may also influence plotting in a CTB-based drawing.
• Plot style controls how the object is printed or exported to PDF.

A clear understanding of these properties helps prevent incorrect line thicknesses, unexpected colors, unreadable drawings, and inconsistent PDF output.

Quick Comparison: Linetype, Lineweight, Color, and Plot Style

Property	Main Function	Visible on Screen	Affects Printed Output	Typical Examples
Linetype	Controls the line pattern	Yes	Yes	Continuous, Hidden, Center, Phantom
Lineweight	Controls physical line thickness	Yes, when display is enabled	Yes	0.13 mm, 0.25 mm, 0.50 mm
Color	Controls object color and layer organization	Yes	Sometimes	ACI red, yellow, green, RGB colors
Plot style	Controls plotted appearance	Mainly in plot preview or layouts	Yes	Black output, screening, grayscale, plotted lineweight

The easiest way to distinguish them is:

• Pattern = linetype
• Thickness = lineweight
• Visible color = color
• Printed appearance = plot style

What Is a Linetype in CAD?

A linetype defines the repeating pattern used to display a line, arc, polyline, circle, or other CAD object.

A linetype may be continuous, dashed, dotted, or built from combinations of long and short segments. Complex linetypes may also contain text or symbols.

Linetypes communicate technical information. They are not simply decorative settings.

Common Linetype Uses

Typical linetypes include:

• Continuous for visible edges
• Hidden for edges located behind another object
• Center for axes and centers of symmetry
• Phantom for alternate positions or moving parts
• Border for boundaries
• Dashdot for special technical references
• Fence for site or property elements
• Gas line for utility drawings

Standard AutoCAD linetypes are usually stored in .LIN files such as:

• acad.lin for imperial environments
• acadiso.lin for metric environments

Custom linetypes can also be created or loaded from separate .LIN files.

Linetype Scale

Selecting the correct linetype is not enough. Its pattern must also display at the correct scale.

Important AutoCAD variables include:

• LTSCALE: controls the global linetype scale in the drawing.
• CELTSCALE: sets the individual linetype scale for newly created objects.
• PSLTSCALE: controls linetype appearance across Paper Space viewports.
• MSLTSCALE: adjusts Model Space linetypes according to the annotation scale.

A dashed line may appear continuous when:

• The linetype scale is too small.
• The linetype scale is too large.
• The object is too short to show a complete pattern.
• The drawing has not been regenerated.
• Model Space and Paper Space scaling settings are inconsistent.

After changing linetype settings, use REGEN or REGENALL when necessary.

What Linetype Does Not Control

A linetype does not control:

• Line thickness
• Object color
• Printed color
• Screening
• Transparency
• Paper size
• Plot scale

A hidden line can be thin or thick. A centerline can use any color. These properties are managed separately.

What Is Lineweight in CAD?

Lineweight controls the physical thickness of a line when the drawing is printed or exported.

Lineweight values are commonly expressed in millimeters or inches of printed width.

Examples include:

• 0.09 mm
• 0.13 mm
• 0.18 mm
• 0.25 mm
• 0.35 mm
• 0.50 mm
• 0.70 mm

Lineweights create a visual hierarchy and make technical drawings easier to read.

Typical Lineweight Uses

A possible lineweight hierarchy may include:

• 0.09 to 0.13 mm for hatches, construction lines, and background details
• 0.18 mm for dimensions, hidden lines, and centerlines
• 0.25 mm for general visible geometry
• 0.35 mm for main outlines
• 0.50 mm or more for cut elements, borders, and major emphasis

These values are examples. The correct system depends on the drawing type, office standard, output scale, and printer.

Displaying Lineweights on Screen

AutoCAD can display lineweights in the drawing area.

Use:

• The LWT button on the status bar
• The LWDISPLAY system variable

The on-screen display is only an approximation. It does not represent the exact physical width that will appear on paper.

The final result should be checked with:

• Plot Preview
• A PDF exported at the correct scale
• A test print when accurate output is important

Lineweight vs. Polyline Width

Lineweight must not be confused with polyline width.

They may look similar on screen, but they are fundamentally different.

Lineweight

Lineweight:

• Is a display and plotting property
• Is expressed as a physical printed thickness
• Is usually measured in millimeters or inches
• Can be assigned to layers or objects
• Does not change the geometric size of the object
• Remains visually consistent when plotted at different drawing scales

For example, a lineweight of 0.25 mm is intended to print approximately 0.25 mm thick.

Polyline Width

Polyline width:

• Is part of the polyline geometry
• Is expressed in drawing units
• Can have a constant width or different start and end widths
• Scales with the drawing and viewport
• Can affect area calculations and visual geometry
• Is created or modified with PLINE, PEDIT, or the Properties palette

For example, a polyline width of 100 means 100 drawing units, not 100 mm on paper unless the drawing units and plot scale produce that result.

When to Use Each One

Use lineweight for:

• Technical drawing hierarchy
• Printed outlines
• Dimensions
• Hatches
• Hidden lines
• Centerlines

Use polyline width for:

• Wide roads
• Diagram paths
• Filled strips
• Graphic symbols
• Objects whose width is part of their geometry

Do not use polyline width as a substitute for a standard plotted lineweight.

What Is Object Color in CAD?

Color controls the visible color of an object or layer.

It is commonly used to:

• Organize drawing layers
• Separate disciplines
• Identify object types
• Distinguish existing and proposed work
• Improve drafting visibility
• Control plotting in a CTB-based workflow

AutoCAD Color Systems

AutoCAD supports several color systems.

AutoCAD Color Index

The AutoCAD Color Index, or ACI, contains indexed colors numbered from 1 to 255.

Common ACI colors include:

• Color 1: red
• Color 2: yellow
• Color 3: green
• Color 4: cyan
• Color 5: blue
• Color 6: magenta
• Color 7: white or black, depending on the background

ACI colors are important because CTB plot style tables use these indexed color numbers.

True Color

True Color uses RGB values and provides millions of possible colors.

An object assigned a True Color does not use the ACI 1–255 color index. As a result, it does not follow the color-to-property mappings defined in a CTB file.

For example, an RGB red object will normally print in that RGB red color even when a monochrome CTB file is selected.

This is an important limitation in CTB-based workflows. Objects that must follow color-dependent plotting rules should normally use ACI colors, not True Color.

Color Books

Color books provide standardized palettes from manufacturers or industry systems.

They are often used for:

• Presentation drawings
• Architectural materials
• Branding
• Rendering
• Color-controlled documentation

Like True Color, color-book colors are not controlled through standard ACI mappings in a CTB file.

What Is a Plot Style in AutoCAD?

A plot style is a set of rules that controls how an object appears when printed or exported to PDF.

Plot styles can control:

• Printed color
• Printed lineweight
• Screening
• Grayscale
• Dithering
• Line end style
• Line join style
• Fill style

AutoCAD uses two plot style systems:

• CTB, or color-dependent plot styles
• STB, or named plot styles

CTB: Color-Dependent Plot Styles

A CTB file assigns plotting properties according to the object’s ACI color number.

Each indexed color from 1 to 255 can have its own settings.

For example:

ACI Color	Screen Color	Printed Color	Printed Lineweight
1	Red	Black	0.50 mm
2	Yellow	Black	0.25 mm
3	Green	Black	0.18 mm
4	Cyan	Black	0.13 mm

In this example, the colors help users distinguish objects on screen, while the CTB file converts them to black lines of different thicknesses.

Advantages of CTB

• Widely used in existing CAD offices
• Simple color-to-lineweight relationship
• Easy to understand when standards are documented
• Suitable for traditional black-and-white technical drawings

Limitations of CTB

• Object color is tied to plotted appearance
• Changing the color may change the printed lineweight
• True Color objects do not follow ACI color mappings
• A missing or incorrect CTB file can completely change the plotted result
• Users must know the meaning assigned to each ACI color

STB: Named Plot Styles

An STB file uses named styles instead of ACI color numbers.

Typical plot style names may include:

• Thin
• Medium
• Heavy
• Screened
• Existing
• Demolition
• Grayscale

The plot style can be assigned to a layer or object independently of its color.

For example, two blue layers may use different named plot styles:

• One may use Thin
• The other may use Heavy

Advantages of STB

• Printed appearance is independent of object color
• Colors can be used freely for organization
• Style names can describe their purpose clearly
• More flexible for complex CAD standards

Limitations of STB

• Less familiar to users accustomed to CTB files
• Requires a carefully defined named-style system
• Can be harder to introduce into an office with many legacy CTB drawings

CTB vs. STB

Feature	CTB	STB
Full Name	Color-Dependent Plot Style	Named Plot Style
File Extension	.ctb	.stb
Main Control Method	ACI color number	Named style
Color Linked to Plotting	Yes	Not necessarily
Supports Named Plot Styles	No	Yes
Flexible Use of Screen Colors	Limited	High
Common in Legacy Drawings	Very common	Less common
Best Use	Established color-based standards	Independent color and plotting control

A drawing uses either CTB mode or STB mode. It does not use both systems at the same time.

How to Identify the Current Plot Style Mode

The read-only system variable PSTYLEMODE identifies the plot style system used by the current drawing.

• PSTYLEMODE = 1: the drawing uses CTB color-dependent plot styles
• PSTYLEMODE = 0: the drawing uses STB named plot styles

Because the variable is read-only, its value cannot be changed directly.

To switch the drawing from one system to the other, use the appropriate conversion commands.

Converting Between CTB and STB

AutoCAD provides two important commands for plot style conversion.

CONVERTPSTYLES

Use CONVERTPSTYLES to convert the current drawing:

• From CTB mode to STB mode
• From STB mode to CTB mode

The command changes the plot style system assigned to the drawing.

Before converting a production drawing, create a backup and verify all layer and plot settings after the conversion.

CONVERTCTB

Use CONVERTCTB to convert a CTB file into an STB file.

The command creates named plot styles based on the settings stored in the original color-dependent table.

A common CTB-to-STB conversion process is:

1. Run CONVERTCTB to create an STB file from the CTB table.
2. Run CONVERTPSTYLES to convert the drawing to named plot styles.
3. Review the styles assigned to layers and objects.
4. Test the output with Plot Preview and a PDF.

Conversion should be treated as a controlled standards change, not as a routine drawing adjustment.

How Linetype, Lineweight, Color, and Plot Style Work Together

These four properties control different parts of the same object appearance.

Architectural Wall

A wall may use:

• Linetype: Continuous
• Lineweight: 0.50 mm
• Color: Red
• Plot style: Black output at 0.50 mm

The linetype identifies the edge as visible. The heavy lineweight gives it graphic importance. The color organizes it on screen. The plot style controls the final printed result.

Hidden Mechanical Edge

A hidden edge may use:

• Linetype: Hidden
• Lineweight: 0.18 mm
• Color: Green
• Plot style: Black output at 0.18 mm

The dashed pattern identifies the edge as hidden, while the thin lineweight keeps it secondary.

Centerline

A centerline may use:

• Linetype: Center
• Lineweight: 0.13 mm
• Color: Cyan
• Plot style: Black output at 0.13 mm

Background Reference

A background reference may use:

• Linetype: Continuous
• Lineweight: 0.09 mm
• Color: Gray
• Plot style: 50% screening
• Transparency: 30%

This combination keeps the reference visible without allowing it to dominate the drawing.

ByLayer, ByBlock, and Direct Assignment

Color, linetype, lineweight, transparency, and plot style can be controlled through the layer, the block, or the individual object.

ByLayer

An object set to ByLayer inherits its properties from its layer.

This is the recommended setting for most CAD objects because it provides centralized control.

Changing the layer properties updates all ByLayer objects on that layer.

ByBlock

An object set to ByBlock can inherit properties from the inserted block reference.

This is mainly useful for geometry inside blocks that must adapt to the layer or properties used when the block is inserted.

Direct Assignment

A direct assignment creates an object-level override.

For example, a line may be placed on a green layer but manually assigned a red color or a different lineweight.

Direct overrides can cause:

• Inconsistent drawings
• Unexpected plotting results
• Difficult troubleshooting
• Problems when layer standards change
• Objects that no longer respond to layer updates

Use direct assignments only for controlled exceptions.

Transparency in CAD Drawings

Transparency controls how much of the geometry behind an object remains visible.

It is useful for:

• Background references
• Hatches
• Existing conditions
• Overlapping zones
• Presentation drawings
• Highlighted areas
• Faded external references

Transparency can be assigned to:

• Layers
• Individual objects
• Hatches
• Solid fills

Like other properties, transparency can normally be set to ByLayer.

TRANSPARENCY

The TRANSPARENCY property controls the transparency level of an object or layer.

A value of 0 means the object is fully opaque. Higher values make it increasingly transparent.

Transparency affects the on-screen display when transparency display is enabled.

PLOTTRANSPARENCYOVERRIDE

The system variable PLOTTRANSPARENCYOVERRIDE controls whether transparency is plotted.

Its values are:

• 0: follows the Plot Transparency setting in the Page Setup or Plot dialog box
• 1: always plots transparency
• 2: never plots transparency

Transparency plotting may increase PDF generation and printing time because transparent objects may require raster processing.

Plot Transparency Option

The Plot transparency option must also be enabled when transparency is expected in the final output, unless it is being forced by the system variable.

If transparency appears on screen but not in the PDF, check:

• The Plot transparency option
• PLOTTRANSPARENCYOVERRIDE
• The selected page setup
• The PDF driver
• The object or layer transparency value

Plot Style vs. Page Setup

A plot style is only one part of the plotting configuration.

A page setup controls:

• Printer or PDF device
• Paper size
• Plot area
• Plot scale
• Orientation
• Plot offset
• CTB or STB file
• Plot lineweights
• Plot transparency
• Plot styles
• Shaded viewport options

A correct CTB or STB file will not produce the expected result if the rest of the page setup is wrong.

Why Printed Lineweights May Not Match the Drawing

Incorrect lineweights can be caused by several settings.

Plot Object Lineweights Is Disabled

The Plot object lineweights option may be disabled in the Plot dialog box or Page Setup.

When this option is off, object lineweights may not be plotted as expected.

Check the active layout’s page setup and verify that Plot object lineweights is enabled.

Plot Styles Are Disabled

The Plot with plot styles option must be enabled when a CTB or STB file is expected to control the output.

If this option is disabled, the selected plot style table may not be applied.

Wrong CTB or STB File

A different plot style table may assign different:

• Lineweights
• Colors
• Screening values
• Grayscale settings

Always confirm the file selected in the active page setup.

Plot Style Overrides the Object Lineweight

A CTB or STB style may specify a fixed lineweight instead of using the object’s own lineweight.

The plotted result will then follow the plot style, not the lineweight shown in the Properties palette.

Lineweight Display Is Disabled

If LWT or LWDISPLAY is off, all objects may appear thin on screen even though they will print with different lineweights.

Direct Object Overrides

Some objects may have direct lineweights or colors instead of ByLayer settings.

Use the Properties palette or SETBYLAYER to identify and correct these overrides.

Different Page Setups

Two layouts may use different:

• Plot style tables
• Plot lineweight settings
• Plot scales
• PDF drivers
• Transparency settings

Do not assume that every layout uses the same configuration.

Polyline Width Is Being Mistaken for Lineweight

A wide polyline may appear extremely thick because its width is part of its geometry.

Changing the CTB lineweight will not remove the polyline’s geometric width.

Check the Global Width, Start Width, and End Width properties.

Common CAD Property Mistakes

Using Color as the Entire CAD Standard

Color alone does not define an object.

A complete layer standard should include:

• Layer name
• Color
• Linetype
• Lineweight
• Transparency
• Plot style when applicable
• Plot or no-plot status

Using True Color in a CTB Workflow

True Color objects do not follow ACI color mappings in CTB files.

Use indexed ACI colors when objects must be controlled through a color-dependent plot style table.

Assigning Too Many Direct Overrides

Direct property assignments make drawings difficult to update and audit.

Keep most objects set to ByLayer.

Using Polyline Width Instead of Lineweight

Polyline width changes the object geometry. Lineweight controls printed thickness.

Use each property for its intended purpose.

Ignoring Plot and Page Setup Options

A correct drawing can still produce an incorrect PDF when:

• Plot object lineweights is disabled
• Plot with plot styles is disabled
• Plot transparency is disabled
• The wrong CTB or STB is selected
• The wrong page setup is active

Assuming the Screen Display Matches the Final Print

The drawing area is not an exact print simulation.

Use Plot Preview and check the exported PDF at the intended paper size.

Best Practices

Use a Standard Layer System

Each layer should have a defined purpose and approved properties.

A layer standard may include:

• Name
• Description
• Color
• Linetype
• Lineweight
• Transparency
• Plot style
• Plot status

Keep Objects Set to ByLayer

Using ByLayer provides:

• Consistent appearance
• Faster revisions
• Easier troubleshooting
• Cleaner files
• Reliable plotting
• Better standards compliance

Use a DWT Template

A standard DWT template can contain:

• Approved layers
• Loaded linetypes
• Text styles
• Dimension styles
• Page setups
• Layouts
• CTB or STB references
• Title blocks
• Standard plotting options

Use a Consistent Plot Style System

Do not mix undocumented plot style files across a project.

Store approved CTB or STB files in a controlled folder and distribute them with the project when necessary.

Review Plot Settings Before Issuing Drawings

Before producing the final PDF:

1. Confirm the correct page setup.
2. Confirm the correct CTB or STB file.
3. Enable Plot with plot styles.
4. Enable Plot object lineweights.
5. Enable Plot transparency when required.
6. Open Plot Preview.
7. Check line patterns and thicknesses.
8. Export a test PDF.
9. Review the PDF at the intended paper size.

Practical Property Comparison Table

Property or Result	Linetype	Lineweight	Color	Plot Style	Polyline Width	Transparency
Dashed pattern	Yes	No	No	No	No	No
Centerline pattern	Yes	No	No	No	No	No
Printed physical thickness	No	Yes	No	Yes	Indirectly through geometry	No
Geometric object width	No	No	No	No	Yes	No
Screen color	No	No	Yes	Limited preview	No	No
Printed color	No	No	Sometimes	Yes	No	No
Grayscale output	No	No	No	Yes	No	No
Screening	No	No	No	Yes	No	No
Faded appearance	No	No	Sometimes	Sometimes	No	Yes
ACI-based plotting	No	No	Yes	CTB	No	No
Named plotting rule	No	No	No	STB	No	No
Stored in external file	.lin	No	No	.ctb or .stb	No	No
Controlled ByLayer	Yes	Yes	Yes	Yes in STB mode	No	Yes
Changes object geometry	No	No	No	No	Yes	No

Troubleshooting FAQ

Why is my CTB or STB file missing?

Possible causes include:

• The file is not installed.
• It is outside the configured Plot Style Table Search Path.
• The drawing uses CTB mode while you are looking for an STB file.
• The drawing uses STB mode while you are looking for a CTB file.
• The file was not transferred with the project.
• The page setup references a plot style table that exists only on another computer.

Use PSTYLEMODE to identify the drawing’s plot style system.

Why do my colors print in color with monochrome.ctb?

The objects may use True Color RGB values or color-book colors instead of ACI indexed colors.

A CTB file controls ACI colors 1 to 255. Replace the True Color assignments with suitable ACI colors when monochrome CTB output is required.

Why are my printed lines thicker than they appear on screen?

Check:

• The selected CTB or STB file
• Plot style lineweight overrides
• The object or layer lineweight
• Polyline width
• The active page setup
• Plot scale
• The PDF driver
• Whether on-screen lineweight display is enabled

Why do my lineweights not print?

Verify that:

• Plot object lineweights is enabled
• Plot with plot styles is enabled when using CTB or STB
• The selected plot style does not ignore object lineweights
• The objects or layers have valid lineweights
• The correct page setup is active

Why does transparency appear on screen but not in the PDF?

Check:

• The Plot transparency option
• PLOTTRANSPARENCYOVERRIDE
• The active page setup
• The selected PDF driver
• The transparency value assigned to the object or layer

Why does a dashed line appear continuous?

Check:

• LTSCALE
• The object linetype scale
• CELTSCALE
• PSLTSCALE
• MSLTSCALE
• The object length
• Whether the correct linetype is loaded

Run REGENALL after making changes.

Why can I not select a CTB file in this drawing?

The drawing may be in STB mode.

Check PSTYLEMODE:

• A value of 1 indicates CTB mode.
• A value of 0 indicates STB mode.

Use CONVERTPSTYLES if the drawing must be converted.

Final Summary

Desired Result	Property or Setting to Change
Create a dashed, hidden, or center pattern	Linetype
Change printed line thickness	Lineweight or plot style
Change the object’s visible color	Color
Control black, grayscale, screening, or plotted thickness	CTB or STB plot style
Create an object with real geometric width	Polyline width
Fade an object or hatch	Transparency
Control several related objects together	Layer properties
Switch between color-dependent and named plot styles	CONVERTPSTYLES
Convert a CTB table into named styles	CONVERTCTB
Identify the current plot style system	PSTYLEMODE
Ensure lineweights are printed	Plot object lineweights
Ensure transparency is printed	Plot transparency

Linetype, lineweight, color, plot style, polyline width, and transparency are separate CAD properties.

The linetype defines the pattern. The lineweight defines the physical printed thickness. The color controls the object’s visible color and may select plotting rules in a CTB workflow. The plot style controls the final printed appearance. Polyline width changes the actual object geometry, while transparency controls how strongly the object appears over other geometry.

For consistent drawings, organize objects with layers, keep most properties set to ByLayer, use an approved DWT template, and apply the same CTB or STB standard throughout the project.