Foil card

Foil cards, officially styled as premium cards, are Magic cards which have a foil or "glossy" finish to them. Urza's Legacy was the first set to feature foil cards in booster packs. However, Lightning Dragon was the first widely-available foil premium card, as it was the card given away at the Urza's Saga prerelease.

Properties

Foil layer on a card back

Underprinting on the foil layer

Physical elements of a Magic card

Final printing

The process involves a special foil layer on the card that highlights certain parts of the artwork over others (the lighter areas are more reflective). All foil cards are black-bordered, even those from the last white-bordered core sets, except those from Unhinged which are silver-bordered.

Rarity

Foil cards are randomly inserted in booster packs. There is approximately one foil in every six packs or six or seven per Booster Pack Box. Mythics, rares and uncommons are harder to locate than commons, just like their unfoiled counterparts. Even common premium cards are rarer than a normal rare, so collectors will find collecting them all to be a challenge. It is very hard to complete a set by purchasing packs, so trading or buying singles is the most economically effective choice.

"Not chase cards"

Although Wizards of the Coast consistently emphasized trading over collecting (referring to Magic: The Gathering and its successors as TCGs), the company recognized that collecting is an important facet of the game's appeal. However, the ever larger print runs of new sets posed fewer challenges to collectors, since stores rarely ran out of an expansion before someone could buy his way to a complete set.

Some other companies offered collectors ultra-rare "chase cards". A chase card is a unique (usually more powerful) card that collectors "chase down" by purchasing lots and lots of cards. For example, in the first edition of the Star Wars CCG, key characters like Luke Skywalker and Darth Vader were ultra-rare cards that both players and collectors were desperate to find. WotC have promised never to print chase cards for Magic. But it may be argued that they have effectively done so anyway, by having a variety of foil mythic rares in a set where one or two are particularly sought after (such as Ugin, the Spirit Dragon). However, the premium Magic cards don't change the game environment at all, since they are duplicates of cards already in the set. However, foil mythics have not been equally rare since the release of foil Buy-a-Box promo cards, that don't appear in a regular version in the set. This phenomenon started with Dominaria.

Slots

Prior to Time Spiral, if a booster pack contained a foil card it would replace the card normally found in that rarity. (i.e. the card Shared Triumph is rare, if there was a foil version in a pack it would replace the card found in the rare slot). Starting with Time Spiral, in every set a foil card replaces a common card regardless of the rarity of the foil card. This means there is a chance of getting two rares (or three in the Innistrad, Dark Ascension, Shadows over Innistrad or Eldritch Moon packs due to the double faced card slot) or even mythic rares in a single booster pack: one foil, and one regular (as well as one double sided in the aforementioned sets).

Producing foils

The foil process has not always been the same. The first foils (which have a shooting star in the lower-left-hand corner of the card) started with Urza's Legacy. The new foiling process (which eliminated print lines) started with 8th Edition. There have been different foiling processes used for release cards, From the Vault: Dragons (double-foiled), etc.

Producing the premium cards presents unique difficulties. They have an extra layer on the card that highlights certain parts of the artwork over others, the "white under-print plate", or "WUP." The holographic foil laminate has to be bonded to this WUP and the regular card back, allowed to "cure" for several weeks, and then overprinted with the matching card art. Foil laminates are tricky on playing cards due to the standards needed for wear resistance and ease of shuffling.

Even trickier are the challenges of printing on the foil background. Opaque areas require a base of white ink, and black and white inks have to be double-printed for readability. Instead of the normal four- or five-color process, premium cards require eight separate color plates. Film alignment has to be precise - even a slight misregistration ruins an entire sheet.

Foils do not pass the bend test; because foil cards have metal on the front, they crease when bent.

From the Vault

From the Vault sets were printed using a special foiling process that was unique to the series. They were printed on a foil stock that is twice as reflective, and treated with a varnish. This resulted in a shinier and stiffer card that had an almost 'holographic' look to them. They feel much slicker to the touch and weigh a notable amount more than a regular foil. From the Vault cards are also exceedingly hard to write on (e.g. an autograph). However, these cards were also notable for having many production issues, like one-pixel vertical lines going down the cardface. They were also more prone to curl, regardless of moisture (but moisture makes it worse).

Quality issues

Foils are notoriously harder to keep in Near Mint condition than non-foil cards. They tend to collect dirt easier, creating a "cloudy" look on the front of the card. They can also have more noticeable print lines (especially on foils made pre-8th Edition, when they changed the foiling process), tend to curl/bend/warp a lot easier (especially in warmer climates), and don't shuffle as well.

Foil-only booster

The Alara Premium Foil Booster pack contained fifteen foil, black-bordered cards from Shards of Alara, Conflux, and Alara Reborn. It was released on January 8, 2010 (MSRP: $11.99).