why does solid white hatch let lines underneath show through?

[jetted4]

I have some drawings that need to be combined into a single, more complex drawing with parts of one component masking parts of another.

We have all colors set to black with defined lineweights, but I discovered from another forum user that color 255,255,255 gives you pure white.  That has worked quite well.

So I tried using a solid hatch of the 255,255,255 white to mask the portions of the component that should not be visible in the combined drawing.  It looks great on the screen.  When printed to PDF it still looks good unless you zoom in.  When you zoom in, the underneath geometry shows through faintly.  (I added a print screen of a small portion)

That won't work for our needs.

I have also tried Wipeout and its a bit of a pain to define complex areas (esp if it has curvature to it) and we also found that it sometimes put a stray line on our resulting print to PDF drawings.

In Adobe Illustrator, I create a white fill object and it fully masks the underneath content completely.

Is there some reliable way to do the same in Autocad?

Otherwise its a pain that I have to delete all of the parts that are supposed to be hidden and then if we make changes to the combined drawing, I have to fix all of the deleted parts to adjust for the changes.

[pendean]

Why would anyone zoom that close if I may ask in your PDF? Just curious.

Is this just a DRAWORDER problem? What have you tried so far with that command?
Which PDF driver are you using?
What settings did you opt for in PLOT command?
Your AutoCAD version as listed in ABOUT command?
Your OS?

[jetted4]

I work for a patent attorney's office.  The US PTO examiners zoom in that close and they objected to a patent application because of the faint marks that were visible on some of the drawings when you zoom in.  Those only occurred where I was using the white solid hatch to mask underneath content.

I did set the draw order and when viewed in Autocad everything appears as it should be with the white hatch masking the underneath content.

Autocad 2021

Windows 10 Pro

We use Adobe Acrobat XI Pro and have printer settings definitions set up required by the US PTO office

In the Plot Manager, plotter says "Adobe PDF Converter", device name we use either "Adobe PDF.pc3" or "Adobe PDF-rendered-fonts.pc3" (in this case it was Adobe PDF.pc3)

[pendean · Accepted solution]

Good to know.

What is your SHADEMODE set to?

What are your PLOT command parameters from my last post?

Test by plotting with the DWG TO PDF.PC3 driver, or any of the ones labelled AUTOCAD PDF, nothing else labelled ADOBE, and see if your issue goes away. If it vanishes you'll have to use the other software you noted for the task you need since you're not allowed to use any other driver. If not, can you share a portion of your DWG file that still has the issue for others to try?

Support for Adobe products are at the forums Adobe hosts over here if you wish to continue with that driver https://community.adobe.com/

[jetted4]

I will try the other plot options you suggested and follow up in the next day or so.  Thanks  🙂

I forgot to note in my previous post that the ghosty lines showing through shows up when printed at normal size also, not just for zooming in on the screen.

Shademode was 2dwireframe.

[jetted4]

I looked at the PDF again, and you can actually make out some of the underneath content even at 100% or at page size of 71%.

But when I printed one of the pages, I could only *barely* tell that there was any faint smudging there.  However, the examiners do study the electronic files closely since defensibility of a patent requires there to be no identifiable mistakes or confusing stray marks of any kind. 

And I am not able to share one of my files since it is a patent application in progress, but I can try to reproduce the problem on another drawing...

[pendean]

Let us know how your testing with the core AutOCAD PDF drivers go, then post a screenshot of your PLOT command "ready to go" from your Adobe and the AutoCAD PDF drivers, lets see your options.

In the AutoCAD PDF drivers you want to ensure you do NOT have LINEMERGE turned on as an option.

[jetted4]

So I tried with 4 different print driver settings:

Both Adobe ones failed, but the DWG TO PDF.PC3 and also the Autocad PDF (High Quality) both worked fine.

Files attached with arrows marking some of the faint bleed through using the two Adobe ones. 

I will see if there is some way to use one of the better plotter options and still have the files formatted the way US PTO requires, since it is a pain and not an ideal use of time to have to trim all of the underneath content because of the bleed through problem and then discover later on that we need to modify the drawing and restore part of what we trimmed away.