Among Eastern Orthodox and Eastern Catholics the Gospel Book (Greek: Εὐαγγέλιον,
shalom b'SHEM Yah'shua HaMashiach Eastern Orthodox
From Wiki
Evangélion) is very important liturgically. It is considered to be an icon of Christ, and is venerated in the same manner as an icon. Traditionally, the Orthodox will never cover the Gospel Book in leather—the skin of a
dead animal—because the words of Christ are considered to be life-giving. Animal
skins are also reminiscent of the Fall of Man, when God fashioned garments of skin
for Adam and Eve after their disobedience (Genesis 3:21). The Apostle Paul speaks
of Christ being the "New Adam" (I_Corinthians 15:22,47-49), and the Orthodox
understand Christ as coming to clothe mankind in the original "garments of light"
which Adam and Eve lost in Paradise. Traditionally, the Gospel is covered in gold, the earthly element which is best symbolizes the glory of Heaven.
If gold is unavailable, the Gospel may be covered in cloth..
Interesting about the dead animal thing.