Engineering manual doesn't last the full 3 hours!

[Stupifyed]

15,000 sp cap

[Zdenka]

15,000 sp cap

Its 12,000 not 15,000. Awards you 4,000 bonus SP total, but the final synth that pushes you over isn't reduced so if you are doing a 700+ SP synth you could end up with ~4,400 SP or so from the manual.

[Falcus]

Its 12,000 not 15,000. Awards you 4,000 bonus SP total, but the final synth that pushes you over isn't reduced so if you are doing a 700+ SP synth you could end up with ~4,400 SP or so from the manual.

Beat me to it :P
But yes, this is correct and I've used quite a few to help level goldsmith.
They might be 200 points but this is gonna help loads when I start levelling Leatherworker more.
Planning to buy 23 of them with the points I got from the Gridania company quests

[Maya_Yam]

I was pretty sure I remembered this being stated in the item description, and sure enough it was:

製作技術を解説した軍用の教練書［製作時の修錬値獲得量が上昇（一定時間経過または一定量上昇で効果消滅）]

But then I checked out the English text online and it say this:

This comprehensive manual on crafting contains knowledge amassed over centuries by well-traveled Disciples of the Hand. It is known to inspire all who read it, granting a temporary boost to skill points earned from synthesis.

The "または一定量上昇で" bit seems to be completely missing from the English translation.