AutoCAD Plot Styles And Pen Tables

Autocad Plot Styles And Pen Tables

What’s in this article?

This guide explains AutoCAD plot styles and pen tables, covering CTB (color-dependent) and STB (named) systems, how to create and edit each type, and how to assign plot styles to layers, objects, and blocks. It shows how to apply plot style tables in Page Setup and the Plot dialog, convert between CTB and STB, share and store .ctb/.stb files, and map pen weights, colors, and screening for plotters and PDFs. Practical troubleshooting, Xref/template behavior, and best practices for office CAD standards are included for reliable, consistent plotted output.

What are AutoCAD Plot Styles and Pen Tables?

AutoCAD plot styles are rule sets that control the appearance of objects at plot/print time. They determine lineweight, screening (plot transparency), color mapping, linetype, and whether an object plots at all. Plot styles come in two formats: color-dependent tables (.ctb), also called pen tables, which map plotted appearance to object color; and named plot styles (.stb), which map appearance to named styles applied to objects or layers. Pen tables are especially useful when you have legacy standards or plotters that expect color-to-pen mappings. In many workflows pen tables ensure consistent lineweights across different printers or when exporting vector PDFs, because the CTB maps RGB/Index colors to physical pen widths and screening values used at plot time.

What is the difference between CTB (color-dependent) and STB (named) plot style tables?

CTB (color-dependent) and STB (named) handle mapping differently. A CTB file associates a plot appearance to each AutoCAD color index (1–255) or true color, so the plotted lineweight, screening, and color depend strictly on an object’s color property. Historically CTBs mirror pen tables used by plotters and are convenient when CAD layers or objects are colored to indicate pen weight rather than meaning. STB (named) uses named plot styles that you assign explicitly to objects, layers, or blocks; the plotted appearance follows the named style, not the object color. STB provides finer control because you can have multiple styles share the same color but plot differently, and it avoids the requirement that color equals plotted pen.

Operational implications matter. CTB is simpler when color usage is consistent and when firms standardize color-to-pen mapping; STB is better for modern layer-based workflows and when you need consistent plotting regardless of color edits. Converting between them requires remapping: converting CTB → STB translates color rules into named styles applied to entities; converting STB → CTB must pick colors to represent each named style. Some third-party plotters and older internal workflows expect CTB/pen assignments; many firms now prefer STB for clarity and template robustness.

How do I create and edit a CTB plot style (pen table) in AutoCAD?

Creating or editing a CTB (pen table) uses the AutoCAD Plot Style Manager and the Plot Style Editor. Start by opening the Plot Style Manager from the Application menu: type PLOTSTYLE or access it via Options → Files → Printer Support File Path. In the manager choose “Add-A-Plot Style Table” to create a new .ctb and pick to start with a copy of the canonical.ctb or a blank table. After creating the file, open it in the Plot Style Table Editor.

• Open Plot Style Manager (PLOTSTYLE or from the Output tab).
• Create or copy a CTB using Add-A-Plot-Style Table wizard.
• Edit pen mapping entries in the Plot Style Editor: select a color index and set lineweight, screening, plot color, and linetype.

In the Plot Style Editor you will see a list of colors (indexed colors and often true color entries). Select a color row and set the plotted color (use “Use Object Color” if you want to preserve color), lineweight (e.g., 0.15 mm, 0.25 mm), screening percentage (0–100%), and whether the object plots or is overridden to “Do not plot.” Screening is important for halftone or faint rules. Save the CTB and place it in your plotters’ support folder or project folder. To test, assign the CTB to a layout and plot to a PDF or printer using the Plot dialog and confirm mapped lineweights visually. Remember: CTB assignments are global by color, so if two layers share a color they will print the same unless object overrides are used.

How do I create and edit an STB (named) plot style table in AutoCAD?

Creating and editing an STB (named) plot style table uses the same Plot Style Manager but with a slightly different workflow because named styles are applied to objects rather than colors. Open the Plot Style Manager, choose Add-A-Plot-Style Table and select the “named plot styles” option to create an .stb. After the file is created, open it with the Plot Style Table Editor. The editor lists named styles (e.g., A, B, Continuous) or allows you to add new names. For each named style you define a plotted color, lineweight, screening, linetype, and whether the object plots.

To apply named styles in a drawing, switch the drawing to use named plot styles: type STYLES or use the “Convert to Named Plot Styles” if converting, or set the “Plot style table” in Page Setup to an STB. You then assign a named plot style to an object or layer via the Properties palette (Plot Style property) or Layer Properties Manager (if you want layer-level default application). Editing an STB later simply modifies the named style definitions; every entity or layer referencing the named style updates at plot time. This approach decouples display color from plotted appearance and is ideal for templates where multiple users need consistent printed outcomes regardless of color choices in-drawing.

How do I assign plot styles to layers, objects, and blocks?

Assign plot styles at layer-level or object-level depending on your workflow. For CTB workflows you typically set layer colors (Layer Properties Manager) so color determines plotted pen. For STB workflows assign a named plot style to layers in Layer Properties Manager by setting the Plot Style column, or to individual objects via the Properties palette (select object and set Plot Style). Blocks inherit their objects’ plot styles; use block editor if you need contained overrides. When inserting dynamic blocks, check whether “Retain Anonymous Block Plot Style” is required.

Object overrides have priority over layer defaults. If a layer specifies a plot style and an individual object has a different assigned plot style, the object assignment wins at plot time. Use the Layer Properties Manager to change many objects at once; use Quick Select to filter and assign plot styles to selected entities. Always test on sample layouts to confirm the intended mapping before batch plotting.

How do I apply plot style tables in Page Setup and the Plot dialog?

To apply a plot style table to a layout, open Page Setup Manager (right-click the layout tab → Page Setup Manager), edit the layout’s page setup, and select the desired Plot style table (CTB or STB) from the drop-down. Alternatively, in the Plot dialog (CTRL+P or Output → Plot) choose the plotter/printer, then select the Plot style table field and pick the .ctb or .stb file. Remember to check the “Plot object lineweights” option and preview before plotting. If you want the setting to be saved with the layout, save the Page Setup; publishing and batch plotting will use the saved page setup mapping.

How do I convert a drawing from CTB to STB or vice versa?

Converting between CTB and STB requires careful remapping to avoid losing intended appearance. In AutoCAD use the CONVERTPSTYLES command: type CONVERTPSTYLES and follow prompts. For CTB → STB conversions the tool creates named plot styles that mirror each CTB color mapping and then assigns those named styles to entities so the look is preserved. Typically AutoCAD creates named styles named after the color index (e.g., Color1Style) and applies them to objects that had that CTB mapping. Review the newly-created named styles in the Plot Style Table Editor and tidy names as needed.

For STB → CTB conversions, AutoCAD uses the CONVERTPSTYLES command as well but must pick colors to represent each named style: the conversion dialog will ask you to choose a color mapping for each named style. This can be lossy if multiple named styles need to map to the same color index, so plan a mapping strategy. Another method: export a listing of named styles and manually create a CTB that replicates the lineweights/screening then use Express Tools or scripting to reassign entity colors matching the new CTB. After conversion, open several representative layouts and plot previews to confirm lineweights, screening, and visibility match expectations. Finally, update templates and Xrefs so future drawings maintain the chosen mode, and communicate the change in office standards to avoid mixed-mode problems.

Where are plot style (.ctb and .stb) files stored and how do I share them across a team?

Plot style files (.ctb and .stb) are stored in the Plot Styles folder under the AutoCAD support directory by default. You can also keep copies in project folders or on a shared network location. To share them across a team, place the files on a central network drive and configure each user’s AutoCAD to include that path in the support file search paths so the Plot Style Manager and Plot dialog list the shared files. Alternatively, include the plot styles in templates and distribute the template to team members so new drawings automatically reference the correct plot style table.

AutoCAD Version	Typical Default Plot Styles Path
AutoCAD 2016–2025 (Windows)	%APPDATA%AutodeskAutoCAD RRenuSupportPlotStyles
AutoCAD (per-install)	C:Program FilesAutodeskAutoCAD SupportPlotStyles
Network / Team Sharing	\servercadplotstyles (recommended central folder)

When using a shared folder, ensure all users have read access and the folder is in the Support File Search Path (Options → Files → Support File Search Path). For better version control, consider placing plot styles under source control or use a managed IT deployment so updates propagate predictably.

How do pen tables affect lineweight, color, screening, and linetype when plotting?

Pen tables (.ctb) map object colors to specific plotted attributes. Lineweight is one of the primary outputs: each color can be assigned a numeric lineweight that the plotter uses regardless of the object’s CAD display weight. Screening (plot transparency or halftone) determines how dark or faint the output is; lower screening percentages produce lighter prints useful for background details. Plot color can be changed at plot time too: you may remap an index color to print as black or a different color. Linetype behavior depends on scaling and plotter support; CTBs can override which linetype color or pattern is used by remapping colors, but true linetype scale/visibility remains controlled by linetype scale and object properties.

With STB the named style sets these attributes per style rather than per color. When plotting to a raster printer or PDF, lineweight and screening translate to pixel thickness and intensity; when plotting with a vector plotter they translate to pen selection and physical stroke width. If a CTB assigns multiple colors to the same pen/lineweight, changing the color in-drawing won’t affect the printed weight — the CTB mapping governs the plotted result. Always preview to ensure dashed/dotted linetypes plot correctly at the selected scale because very thin lineweights may cause dashes to merge when rendered.

How do plot styles impact PDF and printer/plotter output (vector vs raster)?

Plot styles determine how objects are converted to output primitives. For vector outputs (vector PDFs, HPGL, PostScript) lineweights usually translate to scalable vector strokes and color mapping tends to remain precise; CTB entries frequently map to specific pen numbers used by the plotter driver or the vector PDF’s stroke widths. For raster outputs (bitmap PDF, PNG, or non-vector printer), lineweight and screening map to pixel widths and grayscale values; screening can affect perceived darkness but rasterization can soften thin lines and reduce clarity for very fine weights.

Some plotters and drivers interpret CTB pen numbers, producing exact pen swaps for legacy plotters (e.g., pen 1 = 0.30mm). When exporting to PDF, choose “Plot as vector” for linework to remain crisp and searchable; choose raster only when plotting complex raster images. However, mixed content (raster images + vector) sometimes forces rasterization. Verify that the PDF viewer and downstream printing respect the plot style’s color conversions and lineweights — differences between drivers can result in slight appearance changes, so standardized driver settings and shared CTB/STB files help maintain consistency.

How do I create a pen table to match CAD standards or a specific plotter’s pen mapping?

Creating a pen table that matches CAD standards or a plotter’s physical pen mapping requires documenting the target pen widths and colors first. Start by collecting the plotter manufacturer’s pen chart — a table of pen numbers and their actual widths (e.g., Pen 1 = 0.18 mm, Pen 2 = 0.25 mm). Also record any company CAD standards that link CAD color indices or named styles to printed weights. With this data open the Plot Style Manager and create a new CTB (pen table) or edit an existing one. For each color index set the plotted lineweight to the exact pen width you want and set the plotted color to the correct output (black, grayscale, or color).

When matching a plotter’s pen mapping, also set pen assignments for screening and whether the pen should be used for vector plotting versus raster fallback. If your plotter expects pen numbers, use the Plotter Configuration Editor (PC3 manager) to map CTB pen mappings to physical pens if required by the driver. Save a versioned CTB named with the plotter and standard (e.g., PlotterModelA_OfficeStd.ctb).

Validation and iteration are crucial. Print a standard test sheet that includes lines at various weights, common linetypes (solid, dashed, center), and sample hatch fills. Inspect at full scale and measure physical widths with a caliper or compare visually to the standard. Adjust the CTB lineweights and screening based on actual output. When satisfied, deploy the file to the shared plotstyles folder or embed it in the company template. Communicate the change via a standards document so all team members use the correct pen table. For multiple plotters, create separate CTBs named per plotter and maintain a simple matrix indicating which CTB to use for which machine and paper size.

How do I troubleshoot missing or not applied plot style tables?

If a plot style table is missing from the Plot dialog, verify the file exists in AutoCAD’s support search paths. Use Options → Files → Support File Search Path to add the folder containing the .ctb/.stb. If a drawing doesn’t apply the selected plot style, confirm the layout’s Page Setup actually references the file and that you’re not overriding the setting in the plot dialog. For STB/CTB mismatches ensure the drawing is set to use named plot styles or color-dependent plot styles appropriately; use the CONVERTPSTYLES or STYLESMANAGER commands to adapt the drawing mode. Also check file permissions if using a network path — lack of read access can make the table unavailable.

When previews show incorrect lineweights, check the “Display Plot Styles” toggle in the status bar for visual preview of lineweights in the model or layout viewport. If plot output is black and white unexpectedly, ensure the CTB/STB mapping isn’t forcing all colors to print as black. Recreate page setups and try plotting to a PDF to isolate driver vs table problems. Always copy the problematic CTB/STB locally and test with a fresh template to confirm whether the file or the drawing settings are at fault.

How do object and layer overrides interact with plot styles?

Object overrides take precedence over layer defaults. If a layer has a plot style assigned and an individual object has a different plot style or color, the object’s settings apply at plot time. In CTB workflows color controls plotting, but an individual object color override will change which CTB entry applies. In STB workflows assigning a named plot style to an object overrides the layer’s named style. Use this hierarchy intentionally: set broad defaults on layers and apply overrides to handle exceptions. When auditing unexpected outputs, check both layer and object properties for conflicting plot style assignments.

How do I preview lineweights and colors before plotting?

Use the Plot Preview feature in the Plot dialog to see how lineweights and colors will appear when printed. Before that enable “Display Plot Styles” (PS) in the status bar to show the effect of the assigned plot style table directly in the drawing area — this provides a near-live preview of how lineweights render. For more accurate results, preview in the target output device: plot to a high-quality PDF using the same plot style table and driver, then open the PDF and zoom in to check lineweight and screening. These steps help catch scale-related linetype or thin-line problems early.

What are best practices for managing plot styles in office CAD standards?

Standardize and centralize plot styles. Keep validated CTB/STB files in a shared network folder and add that path to user support search paths so everyone sees the same options. Embed the correct plot style references in company templates and sheet layouts so new drawings default correctly. Name plot style files and individual named styles clearly (include plotter name, standard, and version). Maintain a change log or simple version-control approach when altering a shared CTB/STB. Train staff on when to use CTB vs STB and document the office policy: e.g., STB for new projects, CTB for legacy archives.

Regularly audit plotted output by printing a standard QA sheet for each plotter; include lineweights, hatches, and text sizes. Assign a CAD manager to approve changes to plot styles and distribute updates. For large teams, consider locking the templates and plot style folder and pushing updates through IT so accidental local modifications are minimized. Finally, when converting between CTB and STB, plan and test conversions thoroughly and update all templates and Xrefs to prevent mixed-style drawing issues.

How do I import/export plot style tables between versions or other users?

To share plot style tables between users or AutoCAD versions, copy the .ctb/.stb files directly to the target machine’s Plot Styles folder or a shared network folder included in the Support File Search Path. You can export via the Plot Style Manager by using Windows Explorer to copy files. For version compatibility, most .ctb and .stb files are forward and backward compatible across recent AutoCAD releases, but test on the target version. When distributing to many users, include a readme with instructions and the recommended support path.

How do pen tables work with external references (Xrefs) and templates?

Xrefs inherit the plot style settings of the host drawing at plot time. If the host layout uses a CTB or STB, the plotted appearance of Xref entities follows that table and the host’s object/layer overrides. For STB, named styles must exist in the host’s plot style table for named styles referenced in the Xref to map correctly; otherwise AutoCAD may create temporary named styles or revert to defaults. Templates should include the office-standard plot style table and page setups so new drawings and Xrefs created from templates behave predictably. When sharing Xrefs across projects using different plot style approaches, coordinate conversions or unify the plot style policy to avoid inconsistent printed outputs.

How do I fix common problems like plots printing in black and white or incorrect lineweights?

If plots print in black and white unexpectedly, check the selected plot style table: some CTBs map all colors to black. Also verify the “Plot object lineweights” and “Plot with plot styles” checkboxes in the Plot dialog. For incorrect lineweights confirm the CTB/STB assigns the intended lineweight to the color or named style and that the plotter driver supports the requested weight. If the preview shows correct weights but the final plot does not, inspect the driver settings, and try plotting to a vector PDF to isolate driver issues. Reinstall or update the plotter driver if discrepancies persist. Always test with a known-good CTB/STB to isolate the file versus driver problem.

How do plot style tables affect plotting to plotters using .plt or pen assignments?

When plotting to legacy plotters using .plt or HPGL formats, CTB pen number mappings are essential. A CTB can map AutoCAD color indices to pen numbers that the plotter understands; the PC3 configuration often references the CTB to map to physical pens. If the pen table does not match the plotter’s pen widths, output lineweights will be incorrect. When exporting .plt, ensure the chosen CTB’s pen assignments correspond to the target plotter’s pen chart. For STB workflows you must ensure named styles are converted to appropriate pen/color combos at the export stage so the plotter receives the correct pen commands.

What are alternatives to plot style tables for controlling drawing appearance?

Alternatives include strict layer property management and object overrides. Use Layer Properties Manager to control color, lineweight, linetype and plot on/off per layer and enforce templates so layers carry the correct defaults. Use annotation scaling, linetype scaling, and viewport overrides to adjust appearance per layout. For PDF output you can also use printer driver features or post-processing in PDF editors to adjust color or lineweight. However, plot style tables remain the most direct, centralized way to map drawing elements to printed appearance across multiple devices.