Charles was granted a patent on the waterproof fabric in 1823. The Mackintosh raincoat is named for him, even though it is spelled with a “k.” 2. He accomplished a lot at a young age.

But when Macintosh set up his own company, the fabric was improved upon when vulcanised rubber was added to it. The mac is now, the pun very much intended, an umbrella term for any raincoat.