makePDFPresentation - poor shape output quality

Pedro, I tried as you suggested and the tickbox in question for "compress text and line art" changes this line in the .joboptions file:

/CompressPages true

... I tried using makePDFPresentation() twice, once with a .joboptions with this set to true and one without (via PDFSaveOptions .presetFile) but the output was the same both times - shapes/paths being mangled.

I have a working solution using InDesign at the moment which gets Photoshop to output a separate temporary PDF for each layer comp then does this magic:

function indesignCombine(pdfs, filename) {
  var script = [];
  script.push('var input_pdfs = ["' + pdfs.join('", "') + '"]');
  script.push('var doc = app.documents.add();');
  script.push('with (doc.documentPreferences) {');
  script.push(' pageWidth = "392mm";');
  script.push(' pageHeight = "270mm";');
  script.push(' pageOrientation = PageOrientation.landscape;');
  script.push(' pagesPerDocument = input_pdfs.length;');
  script.push(' documentBleedUniformSize = true;');
  script.push(' documentBleedTopOffset = 0;');
  script.push(' facingPages = false;');
  script.push('}');
  script.push('app.pdfPlacePreferences.pdfCrop = PDFCrop.cropMedia;');
  script.push('for (var i=0; i<input_pdfs.length; ++i) doc.pages.place(File(input_pdfs));');

  // TODO: set InDesign pdf options
  script.push('doc.exportFile(ExportFormat.pdfType, File("' + filename + '"));');
  script.push('doc.close(SaveOptions.no);');
  script = script.join("\n");
  var timeout = 120; // max time for indesign bit to run
  var bt = new BridgeTalk;
  bt.target = 'indesign';
  bt.body = script;
  // bt.onResult = function(data) {callback();}; // not needed as sync with .send(timeout)
  bt.onError = function(err) { alert('error: ' + err); };
  bt.onTimeout = function(msg) { alert('InDesign timeout: ' + timeout + 's - please ask Jake to increase the timeout ' + msg); }; // hmm, never called?
  bt.send(timeout); // by specifying a timeout (in seconds) it is sync not async :)
}

I'd love to find a way to do it without using InDesign (and I still need to work on my todo re indesign pdf options and the indesign docs seem really poor for this!) but looks like it's this way for now at least.

How do you create a pdf presentation manually?

File > Automate > PDF Presentation

I'm new to scripting and haven't tried AM, only DOM - wouldn't know where to start with AM.

Record the operation with ScriptingListener.plugin, then isolate the pertinent code and adapt it as needed (wrap it in a function for example).