"Save as PDF" size limitations

[Ignacio28085554rudj]

Hi,

I am generating a CMYK image with 2 additional alpha channels (spot colors). It is large, 34000x15000 pixels.

The image can be saved correctly in TIFF format, but when I try to save it as PDF, the accesible formats are reduced to six or seven options, not showing PDF.
If I modify its width to 30000, then all the format options appear again in the "Save as type:", PDF included.

Does anybody know of this limitation, what the exact limit is and a workaround to generate large PDF files with spot colors?

Thanks,

    Ignacio

[Stephen Marsh]

30,000px on the longest edge is the limit for Photoshop PDF and many other formats.

[Ignacio28085554rudj]

I disagree: I have put together (manually) a PDF with a width of 35000 pixels and Acrobat is able to display it.
So, the limitation is not in the PDF format, but in (some of) the applications generating or handling the file.

[Stephen Marsh]

@Ignacio28085554rudj – Note how I specifically stated Photoshop PDF as opposed to a "different type" of PDF created from another program. This term comes from Adobe, presumably to differentiate it. So we are actually in agreement, it's an application issue.

[Ignacio28085554rudj]

@Stephen_A_Marsh, Thanks for the clarification, I was not aware that PDFs could be classified -- always thought of PDF as a unique format that follows a specification. I understood your sentence as "PDF generated by Photoshop"... Yep, we are in agreement. Good to know, thanks

[Stephen Marsh]

@Ignacio28085554rudj – As Adobe make a distinction in the Save As naming and there is the pixel-based limit in Photoshop as well, Photoshop is an exception to the norm.

https://helpx.adobe.com/au/photoshop/using/saving-pdf-files.html