Foil Badges

In addition to the 5 levels of the standard badge, each trading card set has a foil badge. You earn the foil badge by completing a set of foil versions of the cards for that set. Foil cards are rarer than the standard cards, and thus the foil badge is much more difficult and expensive to obtain.  

Unlike the standard badge which can be crafted 5 times to upgrade it to the highest level, there is only one level of the foil badge. The foil badge is entirely separate from the standard badge. You do not need to have the standard badge at any level to craft the foil one, and crafting the foil badge will not overwrite the standard badge. When viewing recently played games on a steam profile page, owned foil badges will override regular ones of any level though.