#You need to have the spell supplied to craft the scroll.
You need to have the spell supplied to craft the scroll.
Magic Item Creation Rules say:
Note that all items have prerequisites in their descriptions. These prerequisites must be met for the item to be created. Most of the time, they take the form of spells that must be known by the item’s creator (although access through another magic item or spellcaster is allowed). The DC to create a magic item increases by +5 for each prerequisite the caster does not meet. The only exception to this is the requisite item creation feat, which is mandatory. In addition, you cannot create potions, spell-trigger, or spell-completion magic items without meeting their spell prerequisites.
Using Magic Items says:
Spell Completion: This is the activation method for scrolls. A scroll is a spell that is mostly finished. The preparation is done for the caster, so no preparation time is needed beforehand as with normal spellcasting. All that’s left to do is perform the finishing parts of the spellcasting (the final gestures, words, and so on). To use a spell completion item safely, a character must be of high enough level in the right class to cast the spell already. If he can’t already cast the spell, there’s a chance he’ll make a mistake. Activating a spell completion item is a standard action (or the spell’s casting time, whichever is longer) and provokes attacks of opportunity exactly as casting a spell does.
Since scrolls are a Spell-Completion magic item, you are required to meet the spell prerequisites for crafting them.
If we look at the rules for creating scrolls, we see:
The creator must have prepared the spell to be scribed (or must know the spell, in the case of a sorcerer or bard) and must provide any material component or focus the spell requires. A material component is consumed when she begins writing, but a focus is not. (A focus used in scribing a scroll can be reused.) The act of writing triggers the prepared spell, making it unavailable for casting until the character has rested and regained spells. (That is, that spell slot is expended from the caster’s currently prepared spells, just as if it had been cast.)
As a wizard you must have the spell prepared in order to craft a scroll of the spell. Since you are not able to do so, you cannot craft a scroll of it on your own. Therefore, in order to craft a scroll the spell must be supplied during the creation of it.