Nutritive cardboard disks

Cardboard enthusiasts of a certain age may remember W. Schonherr’s somewhat influential 1958 study:

Nutritive Cardboard Disks Combined With Lattice Mesh Membrane Filter as Adjuvant in Hygienic Milk Supervision” [article in German], W. Schonherr, Zentralblatt für Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene, vol. 171, no. 8, June 1958, pp. 616-23.

BONUS: Nutritive cardboard disks play a vital, albeit tiny, role in Case details for Community Trade Mark E6228019 of the UK’s Intellectual Property Office.