The Otago stained-glass artist has used Lexan XL10, which is so strong it can withstand a bullet from a .22 calibre rifle, to protect a restored stained-glass window at Highgate Presbyterian Church this week.
"The window is made of some of the finest handmade English glass from Sunderland.
"This glass is now irreplaceable because the company no longer exists.
"It's a bit of a gem, so it's important that we protect it."
Mr Mackenzie said the 2.4m-high circular window was about 40 years old, and had been badly buckled by years of strong ultraviolet light from the sun.
He spent hours using dental picks, probes and chisels to clean the old weatherproofing material away from the lead and glass before renovating it and covering it with the UV-protectant polycarbonate sheets.
The work is part of a major programme in which the brickwork will be repointed, sealed and painted to stop moisture from damaging the fabric of the building.
