If you get a chance to see how Ilfords plate coating line works
you'd understand why it's expensive and I'd guess the Belgian
facility's not far different.  Production volumes are so low
these are small lines, in Ilford's case taking up the same sort
of floor space as their test/pilot coating line which is used
for test coatings of film and paper and also things like
filters. All emulsions are test coated and checked before final
coating on the main coating line. A short glass plate run is
relatively labour intensive needing two people one loading the
plates the other almost catching at the end of the line. However
when glass plates were the norm different coating lines were in
use and plates were cut to size after coating in many cases.
Commercial plates are now used because of their high
dimensionable stability, their major use is in nuclear research
facilities. It's actually slightly ironic that in fact
Governments have propped up and helped many emulsion
manufactureers, from Ferrania in Italy, Agfa in Ge