Actually, I am thinking that while everyone keeps asking "why aside from munchkinism" well- the answer is someone who wants to make truly amazing items, so the real answer here may be that it will take a breakthrough... unusual for a failed apprentice but in this case not impossible...
You're presuming that a high scribe score has a benefit to book quality, but it doesn't under RAW, with the exception that a skilled scribe (score of 6 or more) adds +1.
So the character has a desire to produce wondrous tractatus of greater than Q17? Why not convince a magus of this vision and have him engage in the research? Why not go off on some quest to find where this wondrous stuff exists that would allow for improved quality with the blessing of the troupe?
Finding mechanical means for creating what you want isn't really possible, IMO. I think the goal (now that you've really stated it) is worthy. Keep in mind, right now, under RAW, Q17 Tractatus are magic items that cannot leave a magical aura, which basically means that they can only be transported directly to another covenant, by whatever means of instantaneous transportation your troupe uses, or basically involves travel to a magic realm. Q17 tractatus are meant to draw people to the covenant to read the book. You could, through this breakthrough, somehow manage to start creating high quality tractatus that can be sold and transported. That is interesting, but as it is outside the scope of RAW, it's really a troupe call as to how you want to get there. Even OR is a troupe discussion, that you want to play in a world where the thing being researched is actually possible.
Here's the thing- the rules don't fit entirely with each other. According to city and guild a workshop total in excess of 12 will generate a quality bonus that is equal to (workshop total-skill)/3 up to a max level of skill/3 for produced goods, and this bonus effects all uses of the item. This bonus is not included in the calculations in covenant which give a max tractus level of 17 (5 com + 3 good teacher+6+3 for materials and clarification). It isn't that 17+ is inherently a magical item, it simply requires clarification which makes it a magical item. With a workshop bonus you should be able to get higher, according to city and guild RAW, though it doesn't explicitly point this out.
Actually in theory according to C&G you can get astronomical, with a good workshop bonus for the percamenarius, the ink maker, the scribe, the bookbinder, and the illustrator you could, with a +2 quality bonus for each have a theoretical +10 quality bonus to the book. (realistically the ink and vellum quality bonus would probably just add to the scribe skill, making it easier to get a +3 instead of a +2 for scribe workshop quality, for a final +7 to the book)
I think I see it now. You're assuming that the finished quality or workmanship should have a much greater affect on the book.
The parchment may be of the finest quality, but it does not improve the work of the scribe. The scribe may have the best inks and materials, including parchment, available and this is reflected in the resonant materials bonuses. The illuminator and book binder also have the same benefits, but resonant materials are capped a +2 to the bonus.
The finished book may be of extraordinary quality and workmanship, but that should certainly have a limit as to how well it conveys the thoughts and ideas in the text. The book might last 100s of years without any special care being taken. But that doesn't affect the quality of the ideas within the book. Resonant Materials consistent with the topic at hand can enhance the experience, but at best, what you're describing will add a +1 to the bonus of the book quality. Keep in mind the effective maximum quality for a tractatus is 17. To get to that, you have to have Com 5, have to be a Good Teacher +3, have to use all skilled professionals +3, and have to use all three resonant Materials +3, finally the standard +3 that all books get. 11 of the 17 quality points comes from the magus, really 13, if you want to include the resonant materials that he had to go on an adventure for, or 14, even when you consider the effort of actually getting the final point of quality from the book through clarification. Edit: The part in italics was added later.
I have no problem with the workmanship of any books being far superior, but that shouldn't provide any quality bonuses above and beyond what is in Covenants.
I would agree with the above, with the caveat that you'd still value books that last longer more highly in a medieval paradigm.
Actually with com 5 and good teacher they can have a quality of 14 before using resonant materials.
It also has an optional rule that 3 points of that come from having a bookbinder, llustrator and scribe with skill 6+. City & guild places 6 as standard quality items, and states that excellent items (workshop total 15+) have a bonus "this bonus is then applied to every activity that the item is used for" studying a book would clearly be something that the book is used for, so it would seem to me that the workshop bonus for scribes, illustrators, and bookbinders would have to apply...
That's exactly what I said, simply restated. 11 points comes from the magus, when considering resonant materials, especially if they involve an adventure, then it becomes 13. Clarifying the book adds another point, too. I'm leaving off the points for skilled professionals.
Yeah, I think you can only get benefits from workshops...
The interesting thing to note here, is that excellent parchment's example is shown to improve the process of making the book. I think this makes an interesting point, that the rolls necessary to make books are completely avoided in the standard hermetic bookmaking process. I do think that if you're going to have bonuses that push the quality beyond 17, then I do think you need to introduce the element of chance into the bookmaking process.
For magical texts I would agree (or at least for tractus, obviously summae can also be boosted by sacrificing level for quality). I think if the covenant is also supporting mundane book writing this should be able to be done as a matter of routine...
One thing about Ars, is that, unless the player(s) want(s) the element of chance, is that seasonal activities are generally considered automatic. Investing the amount of time into making a book, I'd be really bummed about botches. You're changing the nature of the game, quite a bit if every book made is subject to a die roll rather than the ability of the characters.
Not all seasonal activities... experimentation and research for example require stress dice.
Realistically the game was changed with City & Guild, it was just not explicit. City and guild transformed everyday craftsmen, well at least exceptional craftsmen, into something that approached what a magus could do, and in this case possibly exceed it. Technically speaking use of an object for an arcane bonus would also fall under "any use" for exceptional quality items...
Admittedly exceptional quality is not something you should be able to find casually lying around, but given the potential of exceptional items, why wouldn't you be pushing to have lots of very highly trained craftspeople working for you? A sound book on an art (level+quality between 28 and 31) can be transformed into excellent books (level+quality at or above 35) with 3 exceptional, mundane craftsmen. They can even be grogs, if you are willing to put in the time for them to improve their skills and workshops to where they can accomplish this.
If this sounds broken, why was it not addressed before city & guild was published?
It's a choice on the part of the player to do that. Yes, I know so is writing a book.
As I said elsewhere, not everyone should be combined to take everything to the max. City & Guild fits better in a saga where it centers around city life, or there is a lot of trade and barter going on? The idea behind sourcebooks isn't to create rules that allow you to build the greatest thing ever, but to create rules that enable you to tell interesting stories. Is it interesting to make book making, a seasonal activity the result of a die roll? Keep in mind, as mentioned above, experimentation and research do hinge on a die roll, but those are because the characters/players are interested in the possibility of failure or the stories that develop from those situations.
It isn't exactly broken, so much as it exceeds the guidelines of covenants, which, despite City and Guild's description of exceptional and wondrous items is authoritative on the creation of books. If you want to make the book manufacture process more random and the troupe is on board with that, I don't see a problem with it for your saga. But, for me, I'll never subscribe to the idea that you can get tractatus quality above 17 due to the use of exceptional materials. At best, those provide the +1 bonus of purchased resonant materials, and if you want a bigger bonus, you go hunting for those.
It isn't because you used exceptional materials, it's because you used an exceptional scribe, and bookbinder, and illuminator.
The idea that this works in a city but not in a covenant is ludicrous- so I can't have the same workshop used in a city set up inside a covenant? What happens if I take the raw manuscript into a city and have it copied by a master scribe, illustrated by a master illustrator, etc.? If the rules can't work together they shouldn't be in the same game, or at least it should be noted that they are optional and which ones exclude which others.
Exceptional professionals produce exceptional things, resonant materials, are really exceptional things. I never said that it works in a city and not at a covenant, you're really twisting my words. I'm saying that City and Guild was intended to be used by sagas that have a strong focus in playing in Cities. There are some people who play Ars Magica, and don't play with magi. I know, it's amazing to think. Covenants is, and always will be, to me, authoritative on books. Taking that book to a master scribe, illustrator, book binder will net you a +1 for each, and if they use excellent quality materials they will provide an overall +1 as resonant materials. That's it.
Whenever I think I find something like this, something that allows an end-run around previously understood limits, I stop and ask myself, that if it really should exist in the saga. The point isn't that it might be possible, it very well might be. If it is possible, then you need to start asking some hard questions about your saga's cosmology. The first, and most obvious, is why this was never done before? If the only impediment to doing this is acquiring the resources and the logistics, then that's a relatively minor thing in the scope of most Ars Magica sagas. Some stories might focus on logistics issues, especially for newly founded spring covenant sagas, but not all. But anyway, closing the loop and determining why the PCs can do this when it has never been done before is a really important question to answer.
Even accepting the premise that it is possible to create books of Q17 and greater without clarifying the book, then you do have other associated problems, that copies of the book, at least under Cow & Calf: you cannot sell or give that copy of the book away, without the permission of the original seller (who may or may not be the author, and probably should be the author, if he's alive). In short, this is going to trigger a pretty big issue at Grand Tribunal. Guess who sets the Agenda? Prima of House Bonisagus. Prepare for the political fallout, and a response to this revolutionary technique for producing books. If I'm the SG of the saga where this comes up, it's part of what I'd explain to the players most interested in pursuing this course of action. That being said, one could acquire some really poor quality texts, make copies of them and keep them at the covenant, and invite magi from all over to read these vastly improved tractatus...
We also have a magus who has some virtues which allow her to write very strong texts (though so far her understanding of magic has only allowed the production of tracti), and the covenant has discovered some los books from what was a Diedne covenant now in ruins... now those could obviously start some stories if anyone realizes where they came from...