\newcommand\jarshape{%
  \begin{picture}(1800,1500)
    \thicklines
    \put(360,0){\line(-1,3){360}}
    \put(0,1080){\line(3,1){1260}}
    \put(540,1500){\line(1,0){720}}
    \put(1440,0){\line(1,3){360}}
    \put(1800,1080){\line(-3,1){1260}}
    \put(360,0){\line(1,0){1080}}
  \end{picture}}

\newcommand\jarframe[1]{%
 \iframe\jarshape(300,180){1200}{10pt}%
  \ifrch\ifrb:{\separbox{1pt}{#1}}}