 Instead, he argued for the use of camouflage netting, with which he gradually became obsessed, claiming that the Germans were hiding huge armies under immense nets.Camouflage netting was at first considered unimportant by the army; it was not manufactured in large quantities until 1917.Eventually, in 1920, he published a book, "Strategic Camouflage", arguing this case, to critical derision in England but with some support from German newspapers.