Create a shape that hides everything outside the artboards

CarlosCanto suggested this solution: https://forums.adobe.com/message/3802829#3802829

However, this script creates a rectangle for each artboard, and not one common. So the shapes overlap each other.

#target Illustrator  
  
//  script.name = artboardClipping.jsx;  
//  script.description = makes a faux "artboard clipping mask" by drawing a box to cover everything outiside artboards;  
//  script.required = an open document;  
//  script.parent = carlos canto // 7/16/11;  
//  script.elegant = false;  
  
if (app.documents.length > 0)  
    {  
          var idoc = app.activeDocument;  
          var ilayer = idoc.layers.add();  
          ilayer.name = "ArtboardsMasks"  
  
          var newColor = new CMYKColor();  
          newColor.cyan = 0;  
          newColor.magenta = 0;  
          newColor.yellow = 0;  
          newColor.black = 40;  
  
          var msg = "Enter Artboard Mask Percentage Margins \n";  
                      
          var margins = Number(Window.prompt (msg, 400, "Artboard Faux Clipping Mask"));  
          for (i=0; i<idoc.artboards.length; i++)  
               {  
                    var abBounds = idoc.artboards.artboardRect;// left, top, right, bottom  
  
                    var ableft = abBounds[0]; // 0  
                    var abtop = abBounds[1]; // 612  
                    var abwidth = abBounds[2] - ableft; // 792 // width  
                    var abheight = abtop- abBounds[3]; // 0 // height  
                    //$.writeln(abBounds);  
                    var igroup = ilayer.groupItems.add();  
                    igroup.name = "Artboard " + (i+1);  
  
                    var ipath = igroup.pathItems.rectangle(abtop, ableft, abwidth, abheight);  
                    igroup.artworkKnockout = KnockoutState.ENABLED;  
                    ipath2 = ipath.duplicate(ipath,ElementPlacement.PLACEAFTER);  
                    ipath2.resize(margins,margins);  
                    ipath2.filled = true;  
                    ipath2.fillColor = newColor;  
                    ipath.opacity = 0;  
                    ipath.strokeWidth = ipath2.strokeWidth = 0;  
                    igroup.locked = true;  
                    igroup.hidden = true;                      
               }  
     }  
 else   
    {  
        alert ("there are no open documents");  
    }  

maxham12  schrieb Please make such a script: ...

… Please repair my car.

… Please renovate my apartment.

Hi, to help me understand - what's the purpose of this? Is it to take screenshots of the artboards or to quickly preview artwork on screen?'