Note: Merging or flattening layers can't be undone. For this procedure, use a copy of your PDF.
To determine which version of Acrobat you are using, choose Help > About Adobe Acrobat (Windows), or Acrobat > About Acrobat (Mac OS).
For Acrobat 8 Professional or later:
- Make a backup copy of your PDF file by choosing File > Save As and giving the copy a new name.
- Open the copy and choose Advanced > PDF Optimizer. If asked whether you want to save and continue, click Yes.
- Select Discard User Data.
- Select Discard Hidden Layer Content And Flatten Visible Layers, and then click OK.
- When prompted, save the Optimized PDF with another new name.
- Open the Layers panel (if the Layers panel is not visible, choose View > Navigation Panels > Layers). Click the Options pop-up menu, and then select either Merge Layers or Flatten Layers. Merged layers acquire the properties of the layer into which they are merged. Flattening layers discards any layer content that isn't visible onscreen.
- Save the PDF file and try to print it.
- Make a backup copy of your PDF file.
- Open the copy and choose Advanced > PDF Optimizer.
- Click the Clean Up tab.
- Select Remove Hidden Layers Content and Flatten Layers, and then click OK.
- When prompted, save the Optimized PDF with another new name.
- In the Layers panel, choose Options, and then select either Merge Layers or Flatten Layers. Merged layers acquire the properties of the layer into which they are merged. Flattening layers discards any layer content that isn't visible onscreen.
- Save the PDF file and attempt to print it.