I've been enjoying Sex and Sensibility: The Allure of Art Nouveau on BBC 4 enormously (last part tonight 5 April). The first one in the series of 3 covered the work of Alphonse Mucha (said Moo-ka) who caused a sensation in Paris from 1895. His wonderfully ornate style changed the face of commercial art at that time, his new style becoming known as Art Nouveau.
There's a short video clip of that episode here http://www.bbc.co.uk/programmes/p00q9dqp
For those of you who aren't familiar with his work, take a look at this:-
I came across a book on the internet book archive that contains loads of Art Nouveau swirls and patterns, a book that Mucha himself contributed to.
There are lots more of these at http://archive.org/stream/CombinaisonsOrnementales#page/n0/mode/thumb
They're out of copyright and therefore free to be used as you wish so have fun with these and have a great Easter.