Put "Draft" on every graph?

[Zailong Bian]

Hi.

How do you put a word "Draft" in size of 36 points on every graph in a
document?  These graphes are in figure floats. It is not really practical to
add that to the graph individually because there are so many pictures.  It
is possible to add that to every page, but it would be nice to just add to
each graph/float.

Thanks.