I have never run wire to patio speakers outside. I have always fished it from the inside out, directly to the speaker. However, in this case I have to. The run is about 35 feet, coming up from under the deck, up the drainpipe, across the top of the deck to the speaker. I am going to use low voltage landscaping wire which is black. It blends in well with the deck, so you will hardly see it, but what can I use to tack it up? I cannot find anything that will fit around the wire exactly. It's an odd diameter. I want something that will blend in with the wire and keep it nice and tight. Any ideas? Thanks.