He identified it by the quality of the paper and the watermark.
"The Hampstead Mystery"
John R. Watson
Besides, he identified it by his firm's watermark, and he held the plan up to the light and pointed it out to the court.
"The Hampstead Mystery"
John R. Watson
I'm at low-watermark myself, only one bob and a magpie; but as far as it goes, I'll fork out and stump.
"The World's Greatest Books, Vol III"
Arthur Mee and J.A. Hammerton, Eds.