Simplify the following text for a Grade 12 native English-speaking person.
Original: Papyrus scrolls comprised the collection , and although parchment codices were used after 300 BC , the Alexandrian Library is never documented as having switched to parchment , perhaps because of its strong links to the papyrus trade .
Simplified: Papyrus scrolls comprised the collection , and although parchment codices were used predominantly as a more advanced writing material after 300 BC .