Hello Tirolgirl!
Thank you so much for coming back to me ! I didn't know that an eiderdown was also called a 'featherbed'! That could help me with my searches! I thought this was a good site to start a discussion on, as the top (and reverse) has quilting patterns on it.
I live in the UK, but it is interesting to know that people in Germany also have eiderdowns!
I think that some eiderdowns have a mix of other down to help keep the cost a little lower... Do you know any companies that manufacture eiderdowns? I saw one - englisheiderdowns.co.uk but they don't provide any detail on how to make one for yourself ! I might have to take my eiderdown apart
but there is nothing like experimentation.. !