How can I get jpg thumbnails of all clips in my project?

Client is asking for jpgs or thms of all clips in my project. I have about 600 clips. Is there a way to get these easily? Or must I export jpg frames clip by clip? I looked around in the application support files and all I can find there are mcdb files, and they are not organized by project. I tried using the project manager to copy the project, including its video previews, but the previews folder is just empty. All I get from the media cache are peak files. Thanks for any suggestions.