\nopagenumbers
\hsize=2in \vsize=2in
\hoffset=3in

\font\mona=mona300[hf,dek]

\newcount\m
\newcount\n
\def\monalisa{\vbox{\mona \offinterlineskip \n=0
 \loop \hbox{\m=0 \loop \char\n \global\advance\n by 1
   \advance\m by 1 \ifnum\m<10 \repeat}
  \ifnum\n<80 \repeat}}

\monalisa
\bye