Warreyn was the Advertising Coordinator at Puurs, Belgium. This is
one of his earliest works from the 1970s,
a selfmailer on Kaomycin which included a product sample. As
it was unfolded, this colorful piece was to further the physicians'
awareness of 'hidden' bacterial risks even in places where
they might not always be expected. Jan worked for Upjohn
from 1970 to 1996.