So when you make a new card in Decker, it's a totally new blank card, without anything on it.
If you're wanting multiple copies of the wigglypaint drawing card, then what you might need to do is make a copy of the blank wigglypaint card and then paste that in, using the copy card / paste card feature.
But if you're just looking at saving your wigglypaint drawings, depending where you're planning on using them, one thing you can do is make a copy of the wiggly canvas widget (i.e. going into widget mode) and then that can be pasted into a new card or a different deck or what have you.
I hope this makes sense? It might help to know what your end goal is with where you're using the drawings.