Originally South park was a weird animated form 
of a christmas card someone commissioned a couple 
of people to do. They made this 1st clip by 
filming pieces of construction paper. 

When it became an actual series, they use 
extremely powerful and expensive computers to 
simulate construction paper.

Although there's a very very rare chance the 
original construction cutouts may exist, there 
never have been cels to make the series.

TTYL

Karen