When I change printer settings in Xlsx file, then saving and unzip it, I can see printerSettings folder that contains a printerSettings1.bin file.
But, when I do the same with Docx and Pptx - there is no printerSettings folder nor printerSettings1.bin file.
What do I have do to save the Docx/Pptx files while saving the printer settings in a separate file?
Excel, PowerPoint and Word are all different apps. They share quite a few features but each has its own feature set. PPT doesn't save printer properties the way the other Office programs might. In fact, I'm pretty sure it doesn't save anything unless the user specifically goes to File | Options | Advanced and instructs it to use the specified (limited set of) properties when printing the current presentation.
In that case, it stores the properties to be used in \ppt\presProps.XML