Problem is you are buying from an electrical supply house. They are brain dead when it comes to this stuff- it's not an electrical item and the fact that you are an electrician installing it does not change that.
I never said it was an "electrical" supply house. We buy our low volt wire from a wire supplier that deals with LV cable.
What does it matter where we buy the wire? We buy quad shield to avoid the chance of interference. A waste of money? Maybe, but what does it cost you to try and correct a bad signal after the walls are finished? I'd rather not find out.
Why not just use bell wire for your phones and loop jack to jack? It'll work just fine for phones. I just hope the customer doesn't want to use the internet or use the same wire for data.
