In Preview, go to File -> Open Recent -> Clear Menu
Then, completely quit Preview (cmd-Q) and re-open it. Recent documents should be gone from the right click menu and not appear on the application window expose.
In Preview, go to File -> Open Recent -> Clear Menu
Then, completely quit Preview (cmd-Q) and re-open it. Recent documents should be gone from the right click menu and not appear on the application window expose.
Do as above and then in the right click option in the dock icon click on Show Recent (this is in Lion) and the screen will dim but no thumbnails will appear, as they normally would, as you have already cleared the menu. Then click on the desktop to cancel this and when you go back to the dock icon and right click, the recent file names will have disappeared. Bit complicated, isn't it?