In the late 1990s Philippe Matignon tights were very common in the UK, and were among one of the best for quality and value. They seem to have disappeared in the UK now, but are still available in continental Europe.
Their web site at www.philippematignon.org is somewhat unusual as it is a sort of club, and it provides information on their range in tights. Unfortunately only in Italian.
As far as we are aware Philippe Matignon is a brand owned by Filodoro.