This is one of the first things I did with a new trick a friend showed me, mainly a little button in photoshop called 'multiply.' In my stories, there is an alien race called the 'Teur that have retractble claws. With the rise of X-men popularity upon us, I have heard more than my share of 'oh, retractable claws. Like Wolverine?' The answer to that is, 'no,' and in this picture one can get a very basic idea of how the claws work.