A Sorceror and a Wizard want to cooperate to create a Page of Spell Knowledge.
The sorceror has Craft Wondrous Item. The wizard knows Color Spray. Color Spray is a first level spell, so this is going to be a first level Page of Spell Knowledge with a price of 1000 and a cost of 500.
Since neither one has the feat Cooperative Crafting, one of them will be considered the crafter and it will take the normal amount of time. Since the sorceror is the one with Craft Wondrous Item, he is considered the crafter.
Since Color Spray could be cast by a first level wizard, the minimum caster level for the Page is CL1. If the Page is created with CL1, would this limit a sorceror who uses the page to casting Color Spray at CL1, regardless of the sorceror's actual caster level ?
The DC of the spellcraft check that the Sorceror must make is 5 + the CL of the item. If it can be created with a CL of 1, then that's a DC of 6. Can you take 10 on craft checks or does the possibility of ruining your materials preclude that ? If instead the Page must be created at CL17, then that's a DC of 22. Can the wizard "aid another" on this skill check if he's also providing the spell ? If the wizard is unavailable, the sorceror can do this alone by increasing the DC by 5 ?
A Page of Spell Knowledge is not a scroll, you do not use it's caster level to cast a spell. It simply adds the spell to your spells known and then you cast it normally using your caster level.
The listed CL of 17 is to cover 9th level pages. As per this FAQ you can lower the CL to the minimum required to cast the spell (in this case CL1).
So yes, the DC can be set to 6.
Yes, you can take 10 on checks to craft a magic item. FAQ
Aid Another is subject to GM interpretation on whether another spellcaster can aid. Some will state that co-operative crafting is required, others will say it is not. Check with your GM.
Yes, the Sorcerer can do this alone by increasing the DC by 5. FAQ