996018:
Cards are printed on sheets that contains different cards.
A typical press sheet is 11 cards x 11 card for a total of
121 cards per sheet. They control the rarity by how many times a card
appears on the sheet and how often that sheet is printed.
The size may change somewhat, depending on the printer.
Usually the sheets are divided into Common, Uncommon and Rare Sheets.
In Rare Sheets you then can adjust rarities by laying out normal Rares
twice on a print sheet and including Epic Rares only once (That would
make it 242 cards on one sheet for WoW, which I don't think is
probable). This would also get them into the same "slot" when you
randomize things. Sometimes Promo Cards are printed along with the
Rares as well.
Modern Foil cards are printed on their own special paper (which is
already "all glittery") and therefore need their own print sheets (as
well as being specially prepared in layout). Makes them quite expensive
to produce.
I imagine the rub-off legendaries will have to come off a special
printer that can first print the codes and then put the rub-off layer
on top.
I know these are generalities, but that's the way it works. Usually.
retired Medusan Lord
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