What Is An AutoCAD PC3 File?

AutoCAD PC3 files are configuration files used to define and store plotter and printer settings so drawings print or plot consistently across devices.

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What is an AutoCAD PC3 file?

An AutoCAD PC3 (plotter configuration) file stores the device-specific plotting and printing settings for a particular plotter or printer. A PC3 file saves parameters such as paper size, plotter driver options, plot styles (CTB/STB), pen assignments, and other device-specific preferences. Using PC3 files ensures that plotting results remain consistent when printing from different workstations or projects.

Why PC3 files matter

Ensure consistent output: A PC3 file locks in the exact settings needed for a device so line weights, colors, and scale match project standards.
Simplify setup: Users can select a PC3 file instead of reentering many options for each plot.
Shareable configuration: PC3 files can be distributed to team members so everyone uses the same plotter settings.
Device-specific optimization: PC3 lets you configure features unique to a vendor or model (e.g., pen tables, raster/vector switching).

How to create and configure a PC3 file (step-by-step)

Create a new PC3 using Plotter Configuration Editor

In AutoCAD, type PLOTTERMANAGER or open the File > Plotter Manager.
Double-click Add-A-Plotter Wizard (or right-click and choose Add-A-Plotter Wizard).
Follow the wizard to select Device Type (manufacturer and model) or choose a generic driver.
Set the Port (for network/USB printers choose the appropriate port or “None” for file-based outputs).
Name the plotter and save the .pc3 file to the suggested folder or a shared location.

Configure paper sizes, orientation, and quality

Open the created PC3 via Plotter Manager > double-click the PC3 file > click Properties.
Under Device and Document Settings, choose default paper sizes, orientations, and paper source.
Adjust plot quality (resolution / raster/vector options) if the driver exposes them.

Set plot styles (CTB or STB)

In the plot dialog or PC3 properties, choose whether the device uses color-dependent plot style tables (CTB) or named (STB) plot style tables.
If using CTB, assign or point to the desired .ctb file; for STB, choose the named table to control layer-to-style mapping.

Define pen assignments and line weights

Use the Pen Assignments or Pen Table area in PC3 properties to map pen numbers to colors, line weights, or screening values (if the plotter supports pen tables).
Save your settings and test by plotting a sample drawing.

How to apply a PC3 file when plotting from AutoCAD

Open the drawing and press PLOT or CTRL+P.
In the Plotter/Printer drop-down, choose the PC3 file you created.
Select the paper size, plot area, scale, and the plot style table (CTB/STB) if needed.
Preview the plot to check line weights, margins, and orientation.
Click OK to print/plot or Plot to create a file (e.g., exported plot).

Editing, backing up, and sharing PC3 files

Edit PC3 settings through the Plotter Manager or by selecting the plotter in the PLOT dialog and choosing Properties.
Avoid manual text editing of PC3 files; changes should be made through AutoCAD’s UI to prevent corruption.
PC3 files are normally stored in AutoCAD’s plotters folder (user or program data). To share a PC3, copy the file to a shared network folder and instruct users to place it in their plotters folder or use the Plotter Manager to add it.
Always backup PC3 files along with your project templates and CTB/STB tables.

Alternative methods for consistent plotting

Use CTB (color-dependent) or STB (named) plot style tables to control line weights and color mapping across devices.
Export to PDF or DWF with configured settings when recipients do not require direct plotting; use AutoCAD’s DWG to PDF or manufacturer PDF drivers.
Use printer drivers or manufacturer utilities (HP, Epson, Roland) to configure device features outside AutoCAD if advanced options are required.
Use page setups in AutoCAD drawings that reference a PC3 to store plotting presets per layout.

Common errors and fixes

Error: “Plotter not found” or device missing in drop-down
- Fix: Reinstall or update the plotter driver, verify the correct port, or re-add the plotter in Plotter Manager.
Error: Paper size mismatch or clipped plots
- Fix: Confirm the paper size in the PC3 matches the physical tray and check plot margins and printable area in PC3 properties.
Problem: Line weights too thin or too thick
- Fix: Verify correct CTB/STB is applied, check plot scale, and adjust pen assignments in the PC3.
Issue: Dashed or linetype gaps appear wrong after plotting
- Fix: Use PLOT with “Plot object linetypes” enabled and ensure the plot scale matches the linetype scale settings. Also check if plotting as raster vs vector affects linetype rendering.
Problem: Fonts missing or substituted in output
- Fix: Embed required fonts or use AutoCAD SHX/TrueType fonts available on the plotting station. Convert text to geometry only as last resort.
Corrupted or misbehaving PC3 file
- Fix: Restore a backup, recreate the PC3 using Add-A-Plotter Wizard, and reapply required CTB/STB and pen tables.

Best practices and tips

Keep a central repository (network folder) for approved PC3, CTB, and STB files so teams use consistent settings.
Name PC3 files clearly, e.g., “HP_T790_36inch_Color_PC3” to indicate device and intent.
Test a plot preview before committing long or expensive prints.
Save Page Setups in drawings that reference PC3 files so project layouts are portable.
Document plotter-specific requirements (paper stock, pen tables, custom drivers) in a short README alongside the PC3 file.
Update PC3 files after firmware or driver updates on the plotter to keep settings compatible.
When sending files to outside vendors, include the PC3 and CTB files or export to a neutral format like PDF if vendor cannot import PC3.

FAQ

Where does AutoCAD store PC3 files?

AutoCAD stores PC3 files in the user and program plotter folders (e.g., AutoCAD’s Plotters directory under ProgramData or your profile). You can find or add PC3 files via Plotter Manager.

Can I edit a PC3 file with a text editor?

It is not recommended to edit PC3 files with a text editor. Use AutoCAD’s Plotter Manager and the plotter properties dialog to make changes to avoid corruption.

Can I share a PC3 file with other users?

Yes — copy the PC3 to a shared network folder or send it to users and instruct them to add it via Plotter Manager. Also share related CTB/STB and pen table files for full consistency.

What is the difference between PC3 and CTB/STB?

PC3: a device configuration file (plotter/printer settings).
CTB/STB: plot style tables controlling mapping of layer/colors to line weights and other style settings. PC3 references CTB/STB but they are separate files.

Can I use a PC3 file to plot to PDF?

Yes, if the PC3 is configured with a PDF-capable driver or a virtual PDF plotter, you can plot to PDF using that PC3. Alternatively use AutoCAD’s built-in DWG to PDF plotter.

What should I do if plotted output looks different on another computer?

Ensure the other computer has the same PC3, CTB/STB, fonts, and drivers installed. Verify the plot scale and page setup are identical.

How do I set a PC3 as the default plotter for a drawing?

Create or edit a Page Setup in the drawing layout and select the desired PC3. Save the page setup and set it as the default for that layout or template.

Can PC3 files become incompatible after AutoCAD updates?

Occasionally driver or program changes require updating PC3 settings. If a PC3 behaves oddly after an update, recreate it using the Add-A-Plotter Wizard and reapply the same CTB/STB.

How do I recover a corrupted PC3?

Replace it with a backup copy or recreate the PC3 using the Add-A-Plotter Wizard. Keep backups of all plotter-related files to simplify recovery.

Are PC3 files machine-specific?

PC3 files are generally portable, but device drivers and ports must be available on the target machine. If the PC3 references a local port or a manufacturer driver not installed on another machine, you may need to adjust settings or install drivers there.