Due to the lack of any preview option on the pricey armour shaders, the link below is a collection of screens from various shaders so you can get an idea of what it's going to turn out like before dropping the glimmer.
http://www.reddit.com/r/DestinyTheGame/comments/2g3ydx/since_shaders_are_kinda_of_pricey_and_theres_no/
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Can you store shaders and emblems in the vault or do you have to discard them to make more room?