Scrolls: magic-users can make scrolls of spells they know for a cost of 100gp and 1 week for each spell level. Clerics can make scrolls of spells they know for 200gp and 1 week for each spell level. The scroll maker must have access to a spell book and a retail source of scroll making supplies.
Additionally, tribal or impoverished spell casters can make a primitive sort of scroll carved into wooden or clay tablets. These substitute intense incantation and mystic trances for magic ink. They are essentially free of cost but take 6 weeks per spell level to create.