How can I obtain PDF output of design?

You can easily convert your Design SVG into PDF using Inkscape tool in command line mode. Below are suggested keys for the exec command (example is given for PHP).

exec("inkscape -A ".$target_pdf." ".$source_svg." -T -a 0:0:".$svgWidth.":".$svgHeight);

Where
$target_pdf - a full path to the PDF file to be stored;
$source_svg - a full path to the source Design SVG obtained from LiveArt;
$svgWidth, $svgHeight - a viewport measurements you'd like to render. Typically correspond to pixels dimensions of canvas area.

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