I have emailed a few companies on alibaba to try and get some opaque tube to make arches out of. I have asked for 3m lengths. Some ask for min order of 100m to 500m I'm looking at between 30m to 60m for myself. You could even use it to line edges of your house. Just a way to give nice colour dispersion I'm not sure how flexible the tube is but some say it can be used for light advertisement. I'm sure I could make a jig, fill the tube with hot sand and bend it to the correct radius. If anyone else is interested in the tube post here and when I get prices we could work out a bulk buy.