topic Re: Polyline that crosses viewport plot with different thickness in Civil 3D Forum

Polyline that crosses viewport plot with different thickness

henrikCNQJX — Thu, 09 Oct 2025 07:56:55 GMT

Hi, I'm having an issue with plotting where some polylines will have a different thickness after plotting when they cross a viewport.

I've attached two pictures. In one of them I have broken the polylines a small distance before the viewport border and in the other one the polylines are continuous throughout. For some reason the error in thickness stops a small distance after the second viewport has begun even though I only broke the lines on the left side of the border.

This is running Civil 3D 2026.1 Update. Plotted with AutoCAD DWG to PDF plotter.

Re: Polyline that crosses viewport plot with different thickness

ianjchap — Thu, 09 Oct 2025 13:38:43 GMT

Hi @henrikCNQJX,

Do you have a difference in the VP colour (and therefore the plot) on that layer through either of the viewports?

Re: Polyline that crosses viewport plot with different thickness

cwitzel5NL5H — Thu, 09 Oct 2025 14:00:53 GMT

I have been having a similar issue with contours in 2026 also using DWG to PDF. At the edge of the viewport they are thicker than in the center. I keep meaning to try a different PDF printer, but keep running out of time and printing from 2025.

I have some time this morning and may try. I will report back here.

Re: Polyline that crosses viewport plot with different thickness

henrikCNQJX — Thu, 09 Oct 2025 14:03:49 GMT

No difference. And even so the error is visible in both viewports.

Re: Polyline that crosses viewport plot with different thickness

ianjchap — Thu, 09 Oct 2025 14:10:14 GMT

Are you able to share the file?

Re: Polyline that crosses viewport plot with different thickness

henrikCNQJX — Thu, 09 Oct 2025 14:11:04 GMT

I've had this similar issue in previous version (I think 2016 or 2017) and didn't think it would be dependent on the version of Civil 3D. But I just tried plotting in 2025 and had no issue what so ever so that seems to vary then.

Attached a pic of a plot with 2025 and that looks exactly as it should.

Re: Polyline that crosses viewport plot with different thickness

henrikCNQJX — Thu, 09 Oct 2025 14:18:47 GMT

Sure, I've attached a ZIP with the eTransmit of a sample of the file. It does produce the same error for me. A PDF is also attached for comparison.

Re: Polyline that crosses viewport plot with different thickness

ianjchap — Thu, 09 Oct 2025 14:42:41 GMT

Thanks, Can you share your CTB also?

Re: Polyline that crosses viewport plot with different thickness

henrikCNQJX — Thu, 09 Oct 2025 14:53:40 GMT

Should be included in the eTransmit ZIP no? In the PlotCfgs folder.

Re: Polyline that crosses viewport plot with different thickness

ianjchap — Thu, 09 Oct 2025 15:36:43 GMT

Same for me, plots fine using 2024. Do you have any previous version to revert to temprarily that may work?

Re: Polyline that crosses viewport plot with different thickness

henrikCNQJX — Thu, 09 Oct 2025 15:57:11 GMT

Yeah I've got 24 and 25 installed so that's always an option. Would be nice to get to the bottom of the issue though 🙂

Re: Polyline that crosses viewport plot with different thickness

ianjchap — Thu, 09 Oct 2025 16:30:11 GMT

Agreed. If it works with another version at least you'll know it's more likely to be an issue with 2026.1.

Re: Polyline that crosses viewport plot with different thickness

cwitzel5NL5H — Thu, 09 Oct 2025 17:51:47 GMT

I tried a number of PDF drivers and nothing worked well except for Bluebeam, which is it's own annoyance. Affecting both STBs and CTBs.

This is the same drawing printed in 2025 and 2026. A single surface nothing different about them other than the version.

2025:

2026:

We are hopefully starting a ticket through our reseller.

Thanks,

Re: Polyline that crosses viewport plot with different thickness

mgocobachi — Mon, 16 Feb 2026 20:48:27 GMT

I have this issue too, I just discover that for me this only happens when I have a clipped viewport, if you don't need your viewport to be clipped, I suggest deleting it with VPCLIP command

Re: Polyline that crosses viewport plot with different thickness

cwitzel5NL5H — Tue, 17 Feb 2026 15:15:31 GMT

A temporary fix has been posted here:

Plotting or publishing to PDF results in uneven lineweights for some drawings in AutoCAD 2026 products and SSM for Web

This worked for us.

Thanks,