stempel6

\freedraw[color=stempel,opacity=.3,line width=4pt] (0.015,0.02) circle (2.5cm) ;
\freedraw[color=stempel,opacity=.5,line width=3pt] (-0.025,-0.01) circle (2.5cm) ;
\freedraw[color=stempel,opacity=.7,very thick] (0,0) circle (2.5cm) ;