Where can I get/buy pressed Ginkgo leaves?

Hi, I am an artist and have recently started used pressed ginkgo leaves in my mixed media collages.
Do you know where I can buy nicely pressed, flat ginkgo leaves? My sister has been getting them for me from a friend's tree. I hate to keep asking. I ordered some from a pressed flower place in California and they were unusable! They stacked the leaves all together and pressed them......the stems from the stacked leaves made 'bruised" dark lines criss crossing all the leaves. I can't believe they would pressed the leaves in that way.
I would appreciate any information you could give me.
Question by Sue.