I used paper strips for pennants. The paper doesn't break, it bends. So far, not problems with paint flaking off.
For my mounted Samurai, I created my own back banners using a paperclip and pieces of plastic card. I superglued the plastic card to the paperclips. Pictures will be on my painting thread one of these days. The nice thing about the plastic card is that once it is scored, you can snap it, which means that it is reletively easy to create lots of pieces with straight edges.
But here I am talking to a man who drilled out all those HE spear handles...