Lineweight doesn't show in Layouts

Tom Foster · December 9

In the attached dwg, on my m/c,

the three paperspace layouts won't display lineweights - what do you see?

I have these Settings:
PROPUNITS 0
INSUNITS 1
CANNOSCALE 1:1
CELTSCALE 1
LTSCALE 1
MSLTSCALE 1
PSLTSCALE 0 (for each layout and each viewport)
Length units = mm
Page setup>plotscale>scale lineweights ticked

All linework is inside Blocks.

Anthony Apostolaros · December 9

Tom, do you normally see lineweights in a Layout? I don't. Or hardly at all. A 2.11 mm line can look extremely thick in the Model tab, if LWDisplay is turned on and the LWDispScale variable has a high setting. But that same line never looks much thicker than a .60 mm line when viewed in a Layout. LWDispScale isn't supposed to apply to Layouts, and Zoom Factor doesn't seem to affect lineweight display in Layouts as it does in the Model tab.

On the other hand, you should see a very good representation of how a line in a Layout will PRINT if "Display plot styles" is selected in the Page Setup for that Layout. It IS selected in your file, but I can't see how it's supposed to look because I don't have your CTB file.

There's something I don't understand, which may or may not be related to the issue you raised. When I print to PDF from your file, everything is slightly pixellated, especially the curving lines and the colored ones. When I zoom all the way in, the PDF file looks like a bitmap image. That's true even if I change the "Plot style table" to None and use "Plot entity lineweights." When I print from one of my .dwg files, using the same "Print As PDF" configuration, there's no pixellation at all in the PDF file, no matter how far I zoom in. Maybe you're using some setting that I don't know about?

Tom Foster · December 10

Thanks Anthony, about the pdf pixelation - true - visible in Adobe Viewer too. Weird. What happened first is that in layout 22 I clicked something, don't know what, suddenly everything went super-heavy pixelated lineweight, next moment went as it is now - no lineweight displaying in Layouts, and no doubt with the pdf pixelation as well.

Attached is the ctb. Pic ..909 shows Color: Black for Index colors 1 to 249; Pic ..605 shows Color: Use Current for 200 to 255 (the greyscales). So to get coloured lines I have to invent a non-index colour.

I just tried opening the dwg in v24 (instead of v23) - same - so I guess that means it's not corruption in the program (but may be in the dwg file)?

Surprised you find lineweight doesn't show well in Layouts. Attached is pdf showing v useful lineweights (and no pixelation) visible in Adobe Viewer - the fine lines are drawn @ default 0.18, the fat ones 0.35. LWDispScale set at 1 for that file, though thanks for confirming that doesn't affect Layouts.

326B 14.pdf

Screenshot 2025-12-10 103909.png

Screenshot 2025-12-10 104605.png

Tom Foster · December 10

Darn - I just created a new Layout, alongside the three faulty ones, and it's perfect.

This has all happened before, too many times. I'm no longer on subscription, so can't ask Support - but they never say what the fault is, just either copy linework to a virgin dwg, or create a new Profile. Big faff. This time I'd hoped to identify a rectifiable fault instead, but seems didn't need to do that. This and other similar make me think that Bricscad code is fragile.

391-Layout2.pdf

Tom Foster · December 10

No!!! the new Layout's gone again - viewport empty, viewport not selectable. And Layout 22's gone like this screenshot,

Screenshot 2025-12-10 114044.png

again - its Page setup hasn't changed.

Now copying linework to a virgin file, exploding the Blocks for copying, recreating as Blocks in the new file. Better make a new Profile too, and do it in v24.

Tom Foster · December 10

From ChatGPT:
———————————

1. First: you are absolutely right about `LWDISPLAY`

The statement you were given on the Bricsys forum:

“LWDISPLAY affects only Modelspace”

is incorrect.

What actually happens (BricsCAD reality, not documentation)

In BricsCAD v21–v25:

LWDISPLAY is a global display toggle
It does affect Layouts / Paperspace
BUT:
- its state can become desynchronised per drawing
- and sometimes per layout
- especially after:
  - DWG migration
  - layout copying
  - unit fixes (INSUNITS, scale correction)
  - or CTB reassignment

Your 391A.dwg is proof-positive.

So you’re not “seeing something new” — you’ve just tripped over a latent bug that rarely shows itself unless something else goes wrong first.

2. Why 391A.dwg was fixable but 391.dwg is not

This is the key question:

So 391.dwg is corrupt?

Short answer: yes — but in a specific, narrow way.

Long answer: it’s not geometric corruption; it’s display-state corruption.

What’s actually broken in 391.dwg

In 391.dwg:

LWDISPLAY reports On
but the Layout display pipeline is ignoring it
Modelspace obeys it
Plotting may still obey it
Layout display does not

That means:

the system variable value and the internal display flag are out of sync

That’s not user error; that’s a DWG state inconsistency.

3. Why toggling LWDISPLAY didn’t fix 391.dwg

In a healthy drawing:

LWDISPLAY = 0 → 1

forces a redraw and rebinds the display flag.

In a corrupt one:

the variable changes
but the layout display cache doesn’t rebind
so nothing happens

This is exactly the behaviour you’re seeing.

4. Why this suddenly surfaced now

You mentioned earlier:

Immediately into some corruption but can no longer get it sorted.

This lines up with three triggers that are known to destabilise BricsCAD display state:

INSUNITS correction after geometry already exists
(especially copy/paste between drawings)
Upgrading across major versions without Support
(v23 → v25 has a few silent schema changes)
Layout reuse across drawings of different unit provenance

You’ve hit all three.

5. Is 391.dwg “beyond saving”?

No — but it’s not worth nursing either.

You have three sensible options, in increasing order of cleanliness.

✅ Option A — Surgical reset (try this first)

This sometimes rebinds the layout display engine.

In 391.dwg:

Go to Layout 22
Ensure you’re not inside the viewport
LWDISPLAY 0REGENALLLWDISPLAY 1REGENALL
Save, close BricsCAD
Reopen and check

If this works, you’re done.

—————————————It did!

Tom Foster · December 10

deleted

martin@enco.us · December 10

It would be interesting to see what input you gave ChatGPT to get that result.

Anthony Apostolaros · December 10

I was wrong when I wrote earlier that I don't see lineweights in Layouts. I see now that lineweights are in fact displayed in Layouts, whenever LWDisplay is on. The only lineweight difference I see between Layouts and the Model tab is that in Layouts I don't get extreme lineweight differences when zoomed out. That's what gave me the impression that lineweights don't display the same in Layouts.

But I think I was right to say that LWDispScale doesn't affect lineweight display in Layouts. My observation of that appears to confirm what the Bricsys Help Center's LWDispScale page says, that it "Controls the lineweight display scale in Model space."

Tom Foster · December 10

https://forum.bricsys.com/discussion/comment/58042#Comment_58042

It likes lots of detail:
——————————————-
"dwg file attached. Can you see the Model tab and the Layout '22' tab? The latter (Paperspace) doesn't display the different lineweights that are installed in Modelspace.

My Settings are:
PROPUNITS 0
INSUNITS 4
CANNOSCALE 1:1
CELTSCALE 1
LTSCALE 1
MSLTSCALE 1
PSLTSCALE 0 (for each layout and each viewport)
Page setup>plotscale>'scale lineweights' ticked"

and

"The 391A.dwg file I sent is the new one. LWDISPLAY was indeed Off in the Layout(s) and setting it On did cure the non-display in Layout '22'. Well done.
But in the original 391.dwg file. LWDISPLAY is already on but still non-displaying in Layout '22'. So 391.dwg is corrupt? This is the first time that I've seen LWDISPLAY make any difference in a Layout - and I've only just had it confirmed in https://forum.bricsys.com/discussion/40132/lineweight-doesnt-show-in-layouts#latest that it affects only Modelspace - wrong!"

Tom Foster · December 10

Anthony, my experience is that with LWT On (LWDISPLAY = 1) lineweight differences are barely noticeable in Modelspace (so I have Layers of different lineweight, colour coded but printing black) except for very big lineweights. But even small lineweight differences show in Paperspace - now, it seems, provided LWT is on in Paperspace. And those small differences really show nicely in a pdf.

ChatGPT showed that LWDISPLAY in Paperspace was the key - if necessary setting it = 0 then RE then setting it = 1 then RE. I shoulda known - 'switch it off and on again'! It rectified both the original troublesome dwg and the copied-to-new-dwg one, but the original dwg soon went bad again.

Anthony Apostolaros · December 10

Tom, I think maybe there's been a misunderstanding, involving two variables with very similar names. You told ChatGPT that this forum thread confirmed that LWDisplay affects only Modelspace, but I don't see where anyone here said that. I said that about LWDispScale, but not about LWDisplay. I may have implied the latter by my incorrect comment about not seeing much difference in lineweights in Layouts. I apologize for that.

The Help Center page says that LWDispScale is stored in the registry. So the same .dwg file would appear different to you than to me if you're using a different LWDispScale setting. If, as you say, lineweight differences are barely noticeable in Modelspace, maybe you should increase the value of that variable. I normally use 0.6.

Tom Foster · December 10

Beg pardon Anthony, I see now. I've kept DispScale at default(?) 0.55 but now going to 1, not because it makes small lineweights' differences any more visible, but because my linework's got harder to see (age related), on white Modelspace background.

All good now - working away at last!