Hi Last September one bedroom in my house was finishedskimmed,new skirtings etc etc and decorated.I had new vertical blinds fitted into the bay window,first few days they were fine,after about a week i started to notice a kind of white residue on the black blinds. Over time,this got worse,it started off on a few of the blinds and after a couple of months it was on every one. Initially i thought it was faulty fabric,the shop was less than helpful so i contacted the supplier they use, Louvolite,they said they didn't know what it was that was on it until they tested them. They sent new fabric to the shop and new ones were made,they were fitted last week and again the same thing has started to happen again,white residue appearing. The guy from the blind shop took one down,wiped it down with a damp cloth and the white residue disappeared but after a few days it came back. I'm now concerned that it's nothing to do with the fabric and it's condensation as since i took down the heavy curtains in that room and i now just have the blinds,when it's really cold and frosty outside the condenstaion is ridiculous,it just runs down the glass. I didn't know where to post this query,i just wondered if anybody thinks the condensation could cause the white residue on the blinds?