In the USA it is sold as COROPLAST... easy to get small pieces, I think 18 x 24 can be ordered by anyone from Sign Warehouse in Dennison TX in many colors, but larger and thicker is going to be a hassle to find and to ship. Might want to check with your local gas station for obsolete hanger signs as they often used pre printed signs made of the stuff in larger sizes and toss damaged or old ones...Places like 7-11 or Jiffymart usually have signs zip tied to the canopy poles advertising their gas or beer or whatever, and you can use krylon plastic paint to paint the stuff. Election signs are also made from coroplast and those dang pole hanging signs WE BUY HOUSES FOR CASH are the same stuff.
It is available in 3mm and 10 mm thickness IIRC and the heavy stuff is a bit harder to find, I have to order full sheets for my sign shop to get it , and I still have to special order it. I'm out of it right now and don't relish paying for my next large order of the stuff.
It is pretty light, and lasts a few years before the UV really starts to break it down, at least here in TX. If you cover it with sign vinyl it lasts much longer. I use it for my OVERSIZE LOAD signs and have one set that has been on the truck since 2008.
