By using the tutorial in http://psd.tutsplus.com, I create the open envelop by the same way. I'm giving the link of the tutorial.
http://psd.tutsplus.com/tutorials/icon-design/how-to-create-an-envelope-icon-in-photoshop/
Thank you...
http://psd.tutsplus.com/tutorials/icon-design/how-to-create-an-envelope-icon-in-photoshop/
Thank you...