documentclass{standalone}
usepackage{graphicx}
usepackage{tikz}
usetikzlibrary{calc,decorations.pathmorphing,patterns}
usepackage{fontspec}
setmainfont{AlphaMack AOE}

makeatletter
pgfdeclaredecoration{penciline}{initial}{
    state{initial}[width=+pgfdecoratedinputsegmentremainingdistance,auto corner on length=1mm,]{
        pgfpathcurveto%
        {% From
            pgfqpoint{pgfdecoratedinputsegmentremainingdistance}
                            {pgfdecorationsegmentamplitude}
        }
        {%  Control 1
        pgfmathrand
        pgfpointadd{pgfqpoint{pgfdecoratedinputsegmentremainingdistance}{0pt}}
                        {pgfqpoint{-pgfdecorationsegmentaspectpgfdecoratedinputsegmentremainingdistance}%
                                        {pgfmathresultpgfdecorationsegmentamplitude}
                        }
        }
        {%TO
        pgfpointadd{pgfpointdecoratedinputsegmentlast}{pgfpoint{1pt}{1pt}}
        }
    }
    state{final}{}
}
makeatother

begin{document}


begin{tikzpicture}
node[inner sep=0pt,outer sep=0pt]
  (imagebg)
  {includegraphics[width=7cm]{envelope.png}};
node[text width=5cm,font=large]
  at (imagebg.center)
  {TO: A Friend \ over the other \side of the\ world};
draw[white,thick,decoration=penciline,decorate]
  (imagebg.west) -- (imagebg.east) coordinate[pos=0.55] (aux1)
  coordinate (aux2) at ([shift={(20pt,20pt)}]aux1)
  coordinate (aux3) at ([shift={(-20pt,24pt)}]aux1);
draw[overlay,white,thick]
  (aux1) to[out=60,in=180,looseness=1] (aux2)
  (aux2) to[out=0,in=30,looseness=1] (aux1)
  (aux1) to[out=160,in=-90,looseness=1] (aux3)
  (aux3) to[out=90,in=30,looseness=1] (aux1)
  (aux1) to[out=-30] ([shift={(10pt,-20pt)}]aux1)
  (aux1) to[out=-50] ([shift={(0pt,-20pt)}]aux1);

end{tikzpicture}

end{document}