This has some real gaming potential.
Imagine an order of magic users or clerics who seek out scrolls. Members of this order take the scrolls and use this technique to transfer the spells they contain onto their fingernails. The process imbues the recipient with the power to wield the spell. Perhaps at will, perhaps once per day, perhaps once per finger. Protection spells in particular could be made ongoing through this process.
The empowerment of the fingernails wains over time as the fingernails grow out and the text is gradually destroyed. However legends tell of certain masters who take great care to grow their fingernails to extraordinary lengths in order to preserve the enchantments. It’s rumored that some sorcerers have learned to grow their nails so long that multiple spells can be imprinted on them, though attempting to contain such power is a sure path to insanity.
This technique can also be used as a punishment, by imprinting curses on the fingernails of those who have offended the order. The curse cannot be dispelled by normal means and remains in effect until the nails grow out.
Or when they are pulled from the fingers. Or the fingers are removed.
Imprinted nails could add a delightfully macabre way to add magic to your game.