A crafting book can be used to increase workload. In exchange for 10 points of will, a fixed amount of workload can be acquired depending upon the type of book used, as show in the following table. If the book provides more workload than is required to complete the craft then the craft will be completed and surplus workload discarded. You can exchange 10 crafting books of the same level (plus a fee of 10000 Gold) to get 1 crafting book of the next level at the NPC Goncourt