Mr Crawford said carton steel has a high nickel content that allows rusting to an even patina, over which there will be a coat of surface protectant.
"It fits in with a rural environment and a rural town, but in a contemporary way," he said.
Mr Mark said the signs had been a year in the making and council "loved the designs", which most importantly had to come from a Carterton artist and had to highlight the central location of the town.
"Because we are the heart of Wairarapa, physically and geographically we are the centre and we are a community with heart," Mr Mark said.
The signs cost about $50,000 and were synchronised with streetlights and will illuminate at the same time, Mr McWilliams said.