At the age of fourteen Johnston was apprenticed to a cousin in Aberdeen who ran a successful chemist shop, but this was short lived as the fumes from the chemicals made him ill.
In 1800, with financial assistance from his sister Barbara, Johnston leased a small meal mill at Newmill, in Elgin, from a Mr King and began to erect machinery for carding wool with slubbing and spinning jennies.
[3] Johnston began to take in wool from local farms, card and spin it and then sell it back to the farmers for weaving.
By 1811 he had purchased the necessary machinery to process the wool from raw fibre to finished cloth all on one site making Newmill 'vertically' integrated.
[4] In the early days of the business all of Johnston's goods were transported by Alexander on a small gig, travelling the length and breadth of the country.
Johnston was successful in securing the patronage of the Duke of Richmond to weave his estate tweed in 1844, still worn today by the ghillies on the River Spey and at Gordon Castle.
[13] The company holds a royal warrant of appointment for the manufacture of Estate Tweeds, Knitwear and Woven Accessories.