Need help printing images at 1:1 scale

[Joe4 (Joe Babb)]

I do a lot of railing designs. They are not complicated but we’ve found that we can print them full scale 1:1 on 52" wide paper sometimes. I did one project where it worked perfectly. We are running into problems on this project. I’m trying to print rail 2 and it comes out short and that might be because it is at a slight angle to the X axis plane. The other rails go off at other angles so I think that has caused me problems. I tried setting the Cplane to a surface that was formed by Rail 2 and then printing. It came close but not exact. Help as soon as possible, please. There should be a way I can set the printing plane perpendicular to something somehow. I forgot to mention that on some prints the “scale” section of the print dialog grays out and displays very odd numbers.

FtLoudonPark-ramp-261404.3dm (657.8 KB)

Working in Win 11 Rhino 8

Rhino 8 SR30 2026-4-13 (Rhino 8, 8.30.26103.11001, Git hash:master @ 3ad61623b0ac4561e2f13265580c56a9f50596d8)
License type: Commercial, build 2026-04-13
License details: Cloud Zoo

Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 31GB)
.NET 8.0.25

Computer platform: DESKTOP

Standard graphics configuration.
Primary display and OpenGL: NVIDIA GeForce RTX 3060 (NVidia) Memory: 12GB, Driver date: 1-20-2026 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 591.86

Accelerated graphics device with 4 adapter port(s)

• Windows Main Display attached to adapter port 0

Secondary graphics devices.
AMD Radeon™ Graphics (AMD) Memory: 1GB, Driver date: 1-11-2024 (M-D-Y).

Accelerated graphics device with 5 adapter port(s)

• There are no monitors attached to this device!

OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
GPU Tessellation is: On
Redraw scene when viewports are exposed: On
Graphics level being used: OpenGL 4.6 (primary GPU’s maximum)

Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 1-20-2026
Driver Version: 32.0.15.9186
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 12 GB

Rhino plugins that do not ship with Rhino
C:\Users\Jozef\AppData\Roaming\McNeel\Rhinoceros\8.0\Plug-ins\TeDAsharp (ce983e9d-72de-4a79-8832-7c374e6e26de)\1.0.8405.22062\TeDaSharp_060.rhp “TeDAsharp” 1.0.8405.22062

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 8\Plug-ins\Commands.rhp “Commands” 8.30.26103.11001
C:\Program Files\Rhino 8\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 8\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 8.30.26103.11001
C:\Program Files\Rhino 8\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 8.30.26103.11001
C:\Program Files\Rhino 8\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 8\Plug-ins\MeshCommands.rhp “MeshCommands” 8.30.26103.11001
C:\Program Files\Rhino 8\Plug-ins\IronPython\RhinoDLR_Python.rhp “IronPython” 8.30.26103.11001
C:\Program Files\Rhino 8\Plug-ins\RhinoCycles.rhp “RhinoCycles” 8.30.26103.11001
C:\Program Files\Rhino 8\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 8.30.26103.11001
C:\Program Files\Rhino 8\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 8\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 8\Plug-ins\Calc.rhp “Calc”
C:\Program Files\Rhino 8\Plug-ins\SectionTools.rhp “SectionTools”

[Tom_P]

@Joe4

Help as soon as possible, please

@Joe4

It came close but not exact.

use the command
_plan
to get the current viewport look on its cplane in parallel projection ?
does this help ?

Edit:
looking at your file - use namedcplane to store the cplanes that correspond to the geometry / print orientation / …
for example name a cplane “Rail_5”

[Japhy]

Hi Joe,

1. ensure all curves are planar
2. Use Plan command once the plane is established.
3. Named Cplanes / Named Views (named views will save the plane)

skewed linework

I established a plane using SetPlaneBy3Points

use RemapCPlane to get it back to XY, then run SetPt to flatten your objects to the Z zero.

[Joe4 (Joe Babb)]

Okay, I tried the _plan and it seemed to work printing at 1:10 onto 11x17 paper. I’ve done a custom 200x52 using RhinoPDF and sent it in to see if it prints properly.

[Joe4 (Joe Babb)]

Okay, bear with me. I understand from my college drafting days back in the stone age that I must be looking at the “thing” straight on so there’s no distortion of size. That’s why I set the Cplane to a surface created by using edge curves of the rail. And I understand that Setting a plane by 3 points would be the same. The rails I want to print are simple 2D drawings but are oriented in the way the land lays. Where you lose me is RemapCPlane and SetPt. Could you expand on that a little? I guess I could go to the Rhino help site. I would like to know more about what _plan really does.

[Joe4 (Joe Babb)]

When I get down to rail 4 and set the Cplane, that’s okay. But when I type in _plan, it turns the railing vertical instead of horizontal. Is there a way to control that?

My search for _plan on the Rhino help site returned zero results.?

[Japhy]

I am making the assumption the vertical posts will be plumb.

Here i used that methodology to get them all on the xy and flat.

RE_ FtLoudonPark-ramp-261404.3dm (652.7 KB)

the command is Plan, which simply orients the view to whatever Cplane is in the view.

[Joe4 (Joe Babb)]

Looks like the thing I was missing was _plan . Many thanks.

[Joe4 (Joe Babb)]

I found something interesting and a bit troubling. We were still getting errors in the prints of around 0.3% which doesn’t sound like much but if you are building something that must fit something else it could cause heartburn. I found that if I use Microsoft to PDF instead of RhinoPDF then the errors go away. I know we had several issues with printing in the early days of Rhino8. I don’t know if this is a left over one or not.

The problem now is, that I can’t specify a custom size if I use Microsoft to PDF. So is there a chance of fixing RhinoPDF? @Tom_P @Japhy

[Tom_P]

@Joe4

0.3% which doesn’t sound

can you share a rhino file with a namedcplane and an rectangle that matches your paper ?
and maybe a 50mm offset rectangle that should keep the size?

and share both pdfs - the rhinopdf and the microsoft-pdf ?

what happens if you reimport the pdfs to rhino ?
what happens if you open the pdf in illustrator, affinity designer or other vector / desktop publishing programm - and check the size?

my guess you have to go through your workflow step by step with someone of mcneel / support.
(to see wether it s a bug or some incompatibility of pdf version, printer driver, etc…)

good luck - kind regards - tom

[Joe4 (Joe Babb)]

I’ll be glad to share what I’ve got. And if its better to go direct to mcneel support then that’s what I need to do. I am holding up production. Let me try to clarify the issue. We have found, in a previous project, that printing the railing at full scale at a printer who can do 52" wide and up to 200 or so inches long avoids us having to manually layout the thing on our welding table. We can use the print as a template putting the pieces directly on the print. That previous project may have been done in Rhino7, I’m not certain of that, I’ll have to check.

So the issue is the actual printed dimensions measured with a tape versus the annotations on the print. I did the following test in my home office yesterday with 11x17 paper.

So if I print directly to the printer from Rhino, I get zero error. If I print using RhinoPDF to a pdf file, then open it with PDFgear and print clicking the “actual size” button, I get the 0.23% error. The printer doing the 52" wide paper gets similar errors ranging around 0.3% which is unacceptable for the project. It’s pretty clear that RhinoPDF is not correct. Using MicrosoftWritetoPDF gives zero error but I cannot define custom sizes so it is useless.

Unfortunately, I can’t easily do experiments on the bigger print machine. And unfortunately I can’t take my machine to the printers and print directly to their machine.

thanks for your help.

Joe

[Helvetosaur]

If you re-import the RhinoPDF back into Rhino and compare it with the original, can you see/measure the difference? I just tried a test here, file in inches, made a 50" x 200" rectangle, Print>RhinoPDF at 1:1 using a custom document size of 60" x 220", reimported the result into Rhino and it measured 50.000" x 200.000".

[Joe4 (Joe Babb)]

Okay, after responding to Tom I decided to re-do my tests of yesterday. I did open up the PDF file I had produced yesterday via RhinoPDF which was printed a 1:4 to fit a portion of the rail on 11x17. I scaled it 2d by 4 and measured the correct dimension of 54.25". So I printed another PDF today, imported it to Rhino and got the same result.
So, I printed it to my printer and today I got 13 9/16" x 4 = 54.25. Yesterday, I got

13 17/32 x 4 = 54.125". So I did another physical print playing around with the PDFgear viewer and got the correct result again.

Now I am honestly baffled. Yesterday, I thought I had found the answer because my errors matched (kind of) with the printer’s. And also because MicroSoft to PDF gave zero error. It’s easy to point the finger at the printer, but if what he gets on the paper is wrong, then what?

I do realize that you have to be careful when printing a PDF to the printer because I’ve been stung before when I forgot to press “actual size”, but I emphasized that to the printer and his errors are smaller than what you get if you forget and leave it “fit to paper”.

I apologize for the confusion, but yesterday’s results seemed so clear. Any suggestions appreciated. I haven’t changed any of my printer drivers or anything since yesterday, and I am at a loss as how to deal with the errors at the place doing the 52" wide prints.

So, I’ve gone back and clicked “solution” because it appears it is not Rhino. I have identified a different vendor for my prints and will try to resolve the issue with them. If I discover anything new, I’ll post it here for posterity.

[Tom_P]

did you try to reimport the pdf as i suggested above
and also what @Helvetosaur suggested ?
best -tom

[Joe4 (Joe Babb)]

Yes I did. Please see my edits above.

Here’s one I just did in RhinoPDF printed to file at 200"x52".

FtLoudonCrossWalk-1to1-262604.pdf (28.4 KB)

Dimension in blue is measured after importing the file. Looks correct.

[Helvetosaur]

There will always be a microscopic difference because the units for a PDF are printer points, not inches or mm, so there may be a slight conversion error rounded to the nearest printer point (1/72 of an inch IIRC)… However if the PDF re-imports correctly, it seems the problem is not with the creation of the RhinoPDF.

[Joe4 (Joe Babb)]

@Tom_P @Japhy @Helvetosaur

Just a quick note of thanks. You all were patient with me and I learned 2 or 3 things I had not thought of that I can continue to use. We found out that the biggest problem was at the printer who was someone we had not used before.