Inventories



($ in millions)	March 31, 2018		December 31, 2017
Finished products		$1,235		$1,083
Work in process	200		177
Raw materials	493		437
Supplies	35		33
Total Inventories		$1,963		$1,730

Most U.S. inventories are valued using the last-in, first-out method. These inventories represented approximately 32% and 34% of total inventories at March 31, 2018 and December 31, 2017, respectively. If the first-in, first-out method of inventory valuation had been used, inventories would have been $110 million and $103 million higher as of March 31, 2018 and December 31, 2017, respectively.