3. Inventories and Other Deferred Costs

Inventories and other deferred costs consist of the following:


	September 30, 2018		December 31, 2017
	(in thousands)
Raw materials	$	3,830	$	3,200
Work-in-process		3,907		3,745
Finished products		14,714		12,278
Other deferred costs		1,425		1,823

Total inventory and other deferred costs	$	23,876	$	21,046

We had inventory on consignment of $1.4 million at both September 30, 2018 and December 31, 2017.

Other deferred costs relate to our RestoreFlow allograft offering and include costs incurred for the preservation of human vascular tissues available for shipment, tissues currently in active processing, and tissues held in quarantine pending release to implantable status. By federal law, human tissues cannot be bought or sold. Therefore, the vascular tissues we preserve are not held as inventory, and the costs we incur to procure and process them are instead accumulated and deferred. These costs include fixed and variable overhead costs associated with the cryopreservation process, including primarily direct labor costs, tissue recovery fees, inbound freight charges, indirect materials and facilities costs. General and administrative expenses and selling expenses associated with the provision of these services are expensed as incurred.