Vanilla is a product of Lussumo:
Documentation and Support.
It all comes down to two things. 1) Different solvents at different printers. Brenner uses ones that can be easily recycled. Over 90% of the solvents used on our books are recycled. 2) Our books dry by air, not heat set. At the huge printers, all the sheets go through a heat set pass which rapidly cooks in the inks and solvent residue. Our books do not, they air dry, which is obviously slower and seems to allow more of the smell to remain.