A ‘mac’ is a generic name for a waterproof coat, shortened from ‘mackintosh’. In the early 19th century Charles Macintosh (no ‘k’), a chemist in Scotland, came up with a process for sandwiching rubber between two layers of fabric. He patented his rubberised material in 1823 and his company used it to make coats that were glued and taped together at the seams. The problem was that these first macs were heavy, stiff and tended to melt in hot sun!
Meanwhile, Thomas Hancock in England also had a company working on rubber goods, including recycling rubber left-overs. Macintosh and Hancock started to collaborate as Hancock’s rubberised fabric was made in a way that solved the previous issues. Hancock filed a patent for his vulcanised rubber in 1843.
The British Army made use of this invention and, in rainy UK, macs were very popular with the public. Later competition saw a downturn in sales, but today, Mackintosh Ltd and Hancock Vulcanised Articles Ltd both operate in the up-market rainwear sector.