Is the ʼCTBʼ file used to manage line weights during printing in BricsCAD?

ByCADbrief Staff

Short Answer

Yes — in BricsCAD, a CTB file is the standard way to manage line weights during printing when you use color-dependent plot styles through PLOT. The most common professional method is assigning object colors by layer, then selecting the correct CTB in the plot dialog. Limitation: CTB only controls plotted output, not model geometry itself.

What You Need to Know Before

Warning: If your drawing uses true colors or named plot styles instead of index colors, the CTB file may not control lineweights as expected. A very common failure is plotting with the wrong page setup, which silently loads a different plot style table.

How-to

  • Command: PLOT

  • Shortcut: Ctrl+P

  • Quick Steps:

    1. Press Ctrl+P or go to the Output tab on the Ribbon and open Plot.
    2. In the Plot dialog, choose your printer/plotter and select the correct Plot style table (pen assignments) CTB file.
    3. Turn on Plot with plot styles, check the preview, then plot or save the setup for reuse.

Variables & Settings

  • Key Setting: Plot style table (pen assignments)

  • Expert Setting: This option determines which CTB file maps indexed colors to plotted lineweights, screening, and output styles. For consistent office standards, use a saved page setup so every layout calls the same CTB automatically.

Why it Fails

  • Cause 1 (Geometry): Objects use true color instead of indexed color 1–255, so the CTB mapping does not affect them the way you expect.
  • Cause 2 (layers/Locks): Objects are not set ByLayer, or layers use inconsistent colors, which breaks office CTB standards.
  • Cause 3 (Command/Logic): The layout or page setup is using a different plot style table, or Plot with plot styles is turned off.

Quick Fix & Best Practice

  • Quick Fix: Run PLOT, select the correct CTB under Plot style table (pen assignments), and make sure Plot with plot styles is enabled.
  • Manager’s Verdict: Use CTB when your team already follows color-based plotting standards; avoid mixed workflows with true colors unless you control page setups very carefully.

FAQ

Does CTB control lineweights in model space?
No, CTB affects plotted output, not the actual model objects.

Can BricsCAD use STB instead of CTB?
Yes, but only if the drawing is set up for named plot styles.

Why are all my printed lines the same thickness?
The wrong CTB may be loaded, or Plot with plot styles may be disabled.

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