Complex sentence: Clairefontaine is a paper brand made by Exacompta Clairefontaine, a French stationery company, using paper made by the Clairefontaine paper mills.
Split into simpler sentences: Clairefontaine is a paper brand made by Exacompta Clairefontaine, a French stationery company. Using paper made by the Clairefontaine paper mills.