This sheet of paper was made in 1981 presumably just to see how it came out. The beating was obviously not optimised for clarity and the stuff was probably just what was available at the time.
For information about watermarks and how they are made, browse around http://www.motherbedford.com/watermarks/WatermarksMain.htm which is an extremely comprehensive source of information.
© Copyright Simon Barcham Green 2011. Not to be copied or reproduced without written permission