I was reading Cloak of Black Feathers when I thought it would be handy to have a spell to simply produce the cloak at will. When I got done designing the spell, I found it was pretty high level, but have decided to post it anyway because I have some gripes.
I used range personal because it produces an item meant to be carried or worn.
The Duration was Sun for +2 because I thought it inadvisable to have the cape disappear in the middle of using Cloak of Black Feathers.
When I look at the guidelines for Creo Animal, it is Base 5 to create an Individual and that is a single hair, hide, or tusk (as examples). There was nothing lower. It appears that a Base 5 Creo Animal Spell can create one feather. For Creo Corpus, Base 5 creates an entire human corpse. For Creo Herbam, Base 1 creates an entire plant. Creating a corpse of an animal is Base 10. Most other Creo guidelines can produce some of their subject material at a lower level than 5. Animals are supposed to be a "lower" order than people (Corpus), I thought. It just seems odd that it takes Base 5 to produce one hair, or twice as much Base level to create a corpse. Yes, that's complaining, as this spell level seems inordinately high for what it produces.
The Size was +3 because I thought 100 feathers were too few. Although I feel that 1000 feathers would be far more than enough, there wasn't a middle ground. I did think of using Group, but that is 10 individuals, so it would only get 10 feathers from a +2 magnitude shift, less than increasing the Size of Individual by +2 (which is 100 feathers).
The hierarchy of difficulty in Ars Magica seems to be, based on the guidelines:
Animal, most difficult
Under this, it would thus seem that raising a human would be easier than raising an animal, but somehow at the same time, animals can be raised, but humans can't (I know, the "soul" thing).
Raven Cape 40
R: Personal, D: Sun, T: Individual
This spell produces a cape of raven feathers that the caster may wear. It is helpful when a magus wishes to cast Cloak of Black Feathers, but does not have the requisite cape available.
(Base 5, +2 Duration, +3 Size, +2 Processed)
How is making the requisite item for a level 30 spell a level 40 spell?
I am almost willing to apply several negative magnitudes under the central rule, but that's terribly arbitrary, and I would have to toss on three of them to lower it's level below Cloak of Black Feathers.