PDF exports are not 100% black lines?

[Anonymous]

Hi,

I've saved a ArchiCAD layout in both black and white and greyscale then opened it in Arobe Acrobat Pro.I then took the same file and opened it in Illustrator then from I llustrator saved it as a PDF (no edits made)

Below is a screenshot of both files, one directly from ArchiCAD PDF export and opened in Acrobat. The other which has darker lines was exported in the same fashion but them saved as PDF in Illustrator.

Why does this happen? If I want true black lines must I save as PDF, open in Illustrator the save as PDF again?

Thank You

[Laszlo Nagy]

What you can do in ArchiCAD is define a Pen Set that has only black and white pens. Apply that Pen Set to your Drawings and save that as PDF.
That should be black and white even if saved as greyscale.

[Anonymous]

laszlonagy wrote:
What you can do in ArchiCAD is define a Pen Set that has only black and white pens. Apply that Pen Set to your Drawings and save that as PDF.
That should be black and white even if saved as greyscale.

I have only used black lines though, this what I don't understand. I also don't understand how by opening the same PDF in Illustrator, then saving it as PDF, makes the lines appear ' full' black...

Thank You

[Laszlo Nagy]

Curious indeed.
I have no other ideas, unfortunately.

[Erich]

NStocks,

You are certain that your pens are really black and not just something close? If you edit the pen color in RGB the RED GREEN and BLACK sliders are all 0 not just near 0?

Another possible option is to check the Black and White check box in the print dialog.

(sorry I can't speak the the illustrator issue.)

[Anonymous]

Erich wrote:
NStocks,

You are certain that your pens are really black and not just something close? If you edit the pen color in RGB the RED GREEN and BLACK sliders are all 0 not just near 0?

Another possible option is to check the Black and White check box in the print dialog.

(sorry I can't speak the the illustrator issue.)

Nope, it's definitely a black pen colour. The files is a .pla (archive) and the elevations (which have the issues) are unlinked, not that it should make a difference?

On paper things seem black, but on screen when you zoom in (PDF) it is not black.

I've exported it in greyscale and black and white but they are both the same. Please could you tell me the difference between black and white export and greyscale? Does B&W make all dark lines black whereas greyscale will make them into different shades of grey?

Thank You

[Laszlo Nagy]

NStocks wrote:
Please could you tell me the difference between black and white export and greyscale? Does B&W make all dark lines black whereas greyscale will make them into different shades of grey?

Thank You

Yes, with Black and White, all colours are converted into either black or white based on their darkness. It may be that all colors are converted to black except completely white colors.
With grayscale, all colors are converted into one of 256 shades of gray based on their darkness.
You can test this.
Use the "09 Color" Pen Set and place the "Pens and Colors 13" object.
It will display all Pens of the Project. The "09 Color" Pen Set has various shades of several colors.
You can print this to PDF in Black and White and Grayscale and see how the various shades are converted.