I was wondering whether a laboratory text is produced when a Magus investigates an enchanted item ?
Indeed yes, could the laboratory text be used to reproduce the enchanted item ? What if the enchantment isn't Hermetic Magic ?
Thanks 
Nicolas
By the book, lab texts are only written when you create an effect. Even if investigating an enchantment created a lab text, the only thing it'd be good for is helping another magus investigate the same enchantment. I suspect spending a season duplicating the work from the text would let you discover all the same powers (no more, no less) as were discovered in the original work. Of course, the original text is likely to just tell you what those powers are, so there's not much point. I suppose if there were a particularly excessive Shell of Opaque Mysteries, or a very powerful item the previous mage had given up on, it might be useful.
But if you are investigating an Enchantment, then you discover any trigger, then a lab text can help to another for discover that same.
And since you can Experiment with that lab activity, i can see that the lab text is produced.
Hnh. Makes you wonder what side effects of experimentation have on lab investigation.
I think this is a bit iffy, since you're nor creating something per se, so how can you get al altered power? I believe that if the investigation actually changes the enchantment (which may not even be Hermetic) is...not my cuppa.
But on the original question, I don't feel merely investigating an item allows for such easy duplication as a Lab text gives. But the insight of the investigation ought to count for something. But there really isn't a mechanic for such middle-ground, it's either nothing or a Lab Text - which is vitually double efficiency. Perhaps allowing a bonus like Similar Spell? It's suaually not a lot, but having this be dependent on the level of the enchantment...I dunno.
Well it is obvious that the experimentation chart is not always easy to apply, especially when you investigate. Comes down to interpretation and creativity of the SG in my opinion.
I quite like the idea of a bonus, could make a nice houserule 