This really depends on the program you used. Some programs might actually
create Temp files which are worked on and then deleted when you exit the
program. For example Microsoft Word creates a hidden temp file when the
document is opened. You make changes and save to the file and then close
Microsoft Word. The hidden temp file is deleted BUT just as with any deleted
file it is still on the drive it is just inaccessible without the right
software. There are programs that will let you recover a document as it was
prior to the last change being made on it. You can only go back one layer
though. This practise may be common to your graphics program as well. Check
with the manufacturer of the application to see if it is. Then if you know
the location of the cache for the apps temp file you might be able to use a
Recovery program like this one to fine that copy of the file
http://www3.telus.net/mikebike/RESTORATION.html