I've been putting mine in the gallon size ziplock bags and then in a drawer. With the plastic bags, I liked that I could see directly into them vs putting them in a manila envelope, which I had thought of doing as well.
But I love this idea so much better:
...I got two binders and filled them full of clear punch pockets. Each pattern gets a pocket, so that I can keep all the traced pieces and any alterations I've made in the right place. .... The thing I like is that I just have to add a binder to expand the system, and it's cheap.
I am definitely going to try it out.
Thanks so much for posting your idea Joleo (and badskirt for asking)!
