When creating a PDF report of a dashboard, there are two layout modes: Optimize PDF for printing and Preserve existing layout in PDF
Optimize PDF for printingedit
This will create a print friendly PDF with multiple A4 portrait pages, with 2 visualizations per page. This is the layout mode that was always used prior to Kibana 6.1, and will create PDFs similar to the following:
Preserve existing layout in PDFedit
This will create a PDF preserving the existing layout and size of the Visualization or Dashboard, and will create PDFs similar to the following:
When creating a PNG or a PDF report of a visualization, the "Optimize for printing" option will automatically be used.