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liamdmcl2
Inspiring
December 6, 2022
Answered

PDF 1.6 exported from Large Size Canvas is incorrect PPI and also wrong scale when viewed in browser

  • December 6, 2022
  • 5 replies
  • 5351 views

I'm using Illustrator 27.1 working in a large-size canvas and trying to export some 11" x 8.5" artboards with the PDF 1.6 export setting (as reccomended by the Known Issues article). I've tried exporting using both the "Save As" and "Export for Screens" optons, and I'm experiencing 2 issues:

 

Issue #1 - The ppi of downsampled / compressed images is a lot smallet than what's set. If a Downsampling ppi is set for Color Bitmap Images in the PDF export settings, the ppi in the exported PDF is a lot smaller (I'd assume around 10x smaller). I'm only getting crisp images at the max ppi of 2,400.

 

Issue #2 - The PDF is 10x smaller in some viewers. So far, I'm having this issue in Chrome, Edge, and Preview (Mac). I don't have the same scaling issue when viewing it in Acrobat, Gmail, Google Drive, or when importing it into Illustrator.

 

This issue should be replicable with any large-sized canvas, but I've attached the exported PDF with all settings left at the [Illustrator Default] except the downsampling ppi is set to 300.

 

Thank you in advance for your help!

    5 replies

    T
    Test Screen Name
    Legend
    December 12, 2022

    Here is what I believe to be happening. It's complicated. I oversimplify a lot, below, and it's still complicated.

    * Acrobat has a page size limit of 200 x 200 inches. But it also supports a PDF feature called UserUnit, which allows pages to be scaled. So for example if the UserUnit is 10.0, then a page size of 50 x 50 inches is really 500 x 500 inches.

    * Illustrator 24.2 added support for this feature. Before than Illustrator was fully limited to 200 x 200 inches too,

    * In Illustrator 24.2 you can create an artboard up to 2000 x 2000 inches. If the artboard is over 200 x 200 inches, a UserUnit of 10.0 is set. (The only UserUnit Illustrator ever uses is 1.0 or 10.0). 

    * Not a bug, but an inconvenience. If the artboard is over 200 x 200 inches, the UserUnit is always set to 10.0, even if exporting a PDF that is much smaller. (THIS IS HAPPENING IN THIS CASE).

    * Some PDF viewers will ignore UserUnit and show a PDF 1/10 of the size. This is not a bug, it's probably a PDF viewer made for older PDF versions before UserUnit. A lot of apps and plug-ins will ignore UserUnit too. 

    * A bug. UserUser is ignored in setting the ppi for raster effects. The consequence is that if making a PDF from a document with a large artboard (over 200 x 200 inches), then the raster effects are at 1/10 of the specified resolution. Nasty.

     

    This is nasty and I strongly recommend you just avoid artboards over 200 x 200 inches. It does not matter that you are exporting smaller page sizes, the artboard size has done the damage.

      keithb40008408
      keithb40008408
      Participant
      April 16, 2024

      So, was there ever an actual answer or fix to this issue? I have been using Illustrator for years and I am just starting to have this issue. I prepare work in Illustrator nd export it as a press quality pdf with printers marks. I exported a document on a 37" X 61" artboard this morning and had no issies. I tried the same thing on another artboard, this time 31" X 21" and I get the "10X Smaller" warning and the file that is generated is useless. These artboards are no where near 200" X 200". Has Adobe ever solved this issue?

      Ton Frederiks
      Community Expert
      Ton FrederiksCommunity ExpertCorrect answer
      Community Expert
      April 16, 2024

      You may want to add your vote here :

      https://illustrator.uservoice.com/forums/601447-illustrator-desktop-bugs/suggestions/47439314-pdf-files-made-on-large-artboards-get-downscaled-i

        Met1
        Met1
        Legend
        December 12, 2022

        I don't understand why you are using "Large Size Canvas" when your item is 8.5x11...

        From the FAQ on Large Size Canvas troubleshooting Adobe Help page:

        Why does my large-scaled artwork (.ai and .pdf) shrink on opening in a reader app or a browser?
        When you save or export the .ai or .pdf documents created on a large-sized canvas, a scale is applied on the document. On opening this artwork if your reader app or browser is unable to read the scale, the artwork will appear ten times smaller.

        L
        liamdmcl2Author
        Inspiring
        December 12, 2022

        Fair enough re: the scaling issue being listed as a "known issue".

         

        In my specific situation, I'm designing a series of full wall-size murals. Each wall is over 200" W x 120" H. I've illustrated these murals at 1:1 scale on a Large Size canvas, so that when I send them to print, there's no confusion about the scale. I'd like to send someone a PDF proof package that they can print on standard 8.5x11 paper, review, and provide feedback. So I've saved each of these 1:1 scale murals as a Symbol and placed scaled-down copies of the Symbols on a series of 8.5x11 artboards. I then save these artboards as the PDF proof package. When the client provides feedback, I can edit the 1:1 scale murals, and it automatically updates in the proof package.

         

        I often need to design large-scale prints in 1:1 scale and send proofs, so having the PDFs appear properly is important.

          L
          liamdmcl2Author
          Inspiring
          December 12, 2022

          To update here, I've spoken and screen shared with Adobe Support regarding these issues and they've provided the following information:

           

          Issue #1 - The ppi of downsampled / compressed images is a lot smaller than what's set. Adobe Support has agreed this is a bug with the Large Size Canvas and reccomended I follow the workflow of exporting at the artificially higher ppi.

           

          Issue #2 - The PDF is 10x smaller in some viewers. Adobe Support claims this is an issue with the Chrome, Edge, and Preview PDF viewers. Since it's 3 different PDF viewers from 3 different companies, I'm not convinced they're entirely to blame, but there's really nothing I can do.

          Ton Frederiks
          Community Expert
          Ton FrederiksCommunity Expert
          Community Expert
          December 12, 2022

          It is good to hear that Adobe support confirmed the bug (only getting crisp images at downsampling 2400 ppi ), but I would recommend to report it on Uservoice to keep track of the possible solution status.

          Issue #1 - The ppi of downsampled / compressed images is a lot smallet than what's set. If a Downsampling ppi is set for Color Bitmap Images in the PDF export settings, the ppi in the exported PDF is a lot smaller (I'd assume around 10x smaller). I'm only getting crisp images at the max ppi of 2,400.

          Ton Frederiks
          Community Expert
          Ton FrederiksCommunity Expert
          Community Expert
          December 6, 2022

          If I copy your file and paste it into a new 11" x 8.5" document, there is no problem with your settings.

          The large canvas document you shared shows indeed a low res image in Acrobat, while my normal canvas size copy shows a high res image result. 

          It looks like a bug with the Illustrator export to PDF.

          You may want to mention it here:

          https://illustrator.uservoice.com/

          Monika Gause
          Community Expert
          Monika GauseCommunity Expert
          Community Expert
          December 6, 2022

          If it's OK in Acrobat, then it's OK.

          Other PDF viewers don't support everything in a PDF.

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