Clipped Viewport Causing thick lines where Polylines cross it.

[jbaxerGA33V]

Clipped Viewport Causing thick lines where Polylines cross it.

The lines only appear thicker when printed, and appear in multiple pdf viewers

Things I've tried: 

Viewport Clip polyline - global width of 0

Frame set to 2

attempted to change the plot to "DWG to PDF.pc3"

changed the object lineweights to 0 (using ctb)

changed linetype settings, and a bunch of other recommended fixes from Gemini AI

Removing the clip, and using wipeouts appears to fix the problem, however there are scenarios that require clip in our template. So I need this fixed. 

[N8DAWGG]

Ok finally someone else reporting this. I've been experiencing this as well and it affects not just lines, but anything printed.

Text that gets too close for me will be made thicker, and for lines it's only the portion of the line that is connected to the edge of the viewport.

In my below example, those are dashed lines. Only the dash that comes close is made bold even though they're the same object. Yet on another post I made where I shared a different example, when it's a continuous line, the entire line is made thicker. (please note that some of the objects in my below example are drawn in paper space and are not effected)

[_H_R_]

a workaround perhapse?
it seems in my situation, if you freeze the layer the mview is on the lines will have the correct thickness

[elusiv]

Been having this exact issue - freezing the layer the viewport is on worked for us.

[cwitzel5NL5H]

But that is not really a workable solution on a 100 sheet set.  Also difficult to tell end users, "Do this work around, then undo it after you print"

[elusiv]

Well, in theory if your 100 sheets are in the drawing, you just freeze the layer overall. At least, that worked for me. But, I agree it is not ideal - especially when your plans are split over multiple drawings. But it can tie us over until we revert back to C3D 2025 or a fix is issued.

[rl_jackson]

Chris,

I think this is STB related. I have seen similar issues but worked around it

[billhynsonQ59TQ]

Freezing the viewport layer seems to work only occasionally in my case, whereas other times the limits of the viewport go away as well then the lines will extend into other text/items on the sheet and it no longer is a practical solution.

rl_jackson-

Is this something you have identified directly in the STB or do you not run into this issue with how you use the software?

[CGBenner]

@billhynsonQ59TQ @Ash_Christensen and others.

It appears that this has been logged as a defect by both the AutoCAD and Civil 3D teams with the defect numbers given in this thread.  It is possible but not guaranteed that the defect could be fixed in a future update or release to the software.  I recommend keeping an eye on your Autodesk account for updates, and check the "What's New" for these to see if it has been addressed.  I will also try to reach out to the relevant teams and ask them to update this thread when / if they have new information on this.

In the meantime, have any of the suggested workarounds in this thread worked for anyone?

[_H_R_]

Hi billhynsonQ59TQ

I create the viewport from a closed polyline (Mview -> Object -> Select
Polyline). Both entities (polyline and viewport) are on the same layer.
After the layout is set up, the layer of the viewport(s) can be frozen.
Only the border is then no longer visible, but the view itself remains
visible. In my case, without thickening. The text doesn't either.

Sincerely,

Hans

[Chuck_L_AKS]

We are experiencing the same issue. No problems using C3D 2024. Problem with C3D 2026. 

The images below are the same drawing printed with Civil 3D 2026.2/AutoCAD 2026.1.1

First image has a clipped viewport and displays the first segment of lines heavier and any text near the viewport edge. Note the contours. 

This second image is the same drawing with the viewport clipping removed. 

Line and text example. Note the segment of the reversing curb and how it changes at the geometry point. 

Clipped VP

No VP clipping

Viewport is visible for clarity. 

[kurtebaldwin]

Same plotting issue here. No workarounds have worked for us. 

[igi_pop]

Good thing i started going trough the forum again, cause I might have gone without noticing this, i rarely do clips.

I've just tinkered around with it, and it IS linked to whatever value you setup for your DEFAULT LINEWEIGHT, something about it.

If you set your layers to "default", and object styles to "default", and the default lineweight to 0.00 - it will plot it consistently. With no thick-thin play.

If you change layer LW, or object LW trough style, even if you do both, or either, it will plot to the DEFAULT value near the border as you described, as if you never set it up.. 

Maybe with this info, the powers can figure out what's causing it and reproduce it consistently.

It is a weird thing, and it kinda dissapears when you zoom in on your PDF.

Can you all confirm that the problem propagates to a physical print?

Cheers,

Iggy

[Chuck_L_AKS]

This was first discovered on a paper print. Everything is printed to PDF, then printed on paper. We thought it could be different printers. But the only common element was the clipped viewport. 

[billhynsonQ59TQ]

While the print preview in autocad appears to print normal, once it has been printed to pdf it becomes apparent, and the physical print of the sheet is even more obvious.

[billhynsonQ59TQ]

@CGBenner - 

Have you had any updates from the autodesk or figured out any additional possible fixes to this issue?  We are still experiencing the same problems as of now.

Have any of you that were able to submit a support ticket heard anything back?

[chriscowgill7373]

Have you tried the hotfix that was released regarding this issue

https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/Plotting-to-PDF-re...

[kurtebaldwin]

I have tried this hotfix and can confirm it resolved the issue for us.

[awkeller88]

I am also having the same issue. The problem is in Civil 3d 2026, not in Civil 3d 2024, and appears to be connected to the "Plot Object Lineweights" in the page setup manager.

[cwitzel5NL5H]

There is a hotfix.  https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/Plotting-to-PDF-re...

I don't believe it was include in the service Pack.  I don't know if it is an issue for 2027.

Thanks,

[chriscowgill7373]

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@cwitzel5NL5H wrote:

There is a hotfix.  https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/Plotting-to-PDF-re...

I don't believe it was include in the service Pack.  I don't know if it is an issue for 2027.

Thanks,

---

There haven't been any full on updates released since that hotfix (to my knowledge) and from what I have heard from those on 2027, it is not an issue there.