Foil question

[Bluenote20]

I have been playing magic online for the past 5 years and haven't purchased physical mtg cards since tempest, so I missed the whole foil uprising. I recently bought 4 foil Serendib Efreet's from the "From the Vault: Exiled" set and the whole entire card is foil. I purchased the Graveborn all foil deck yesterday and noticed only certain parts of the card are done in foil accents. Did they shy away from a full foil card for visibility reasons or any other certain reason?

[Queezle]

Its lots o' money to make so wizards doesnt often to full foil art. ah well.

[BlackJester]

From the Vault has a special and separate foil printing technique.  Not all foils are done the same way.