Maclennan studied textile design in the 70s and then joined a leading London design consultancy, managing a team of designers to develop the Japanese market.
In 1982, he set up East Central Studios, a design studio specialising in colour forecasting, textiles, fashion design and the associated promotion, marketing and branding.
MacLennan is known for his scope of expertise in this field, and has also acted as external examiner at Chelsea School of Art, Brighton University and the Royal College of Art, and later also as visiting professor. Other education-focussed activities include being a regular jury member for the RSA design competitions and as a judge for Texprint.
In 1995, his studio co-created the design and marketing magazine, Viewpoint, and acted as a creative director until issue 10. He is also a contributing trend editor for Textile View magazine.
Commercial work included consulting in depth with global fibre brands as well as textile mills, manufacturers and retailers, combining design innovation with market development and communication strategies.
Building on the launch of the first new fibre in over 20 years, Ingeo, where the key driver and point of difference were its powerful eco sustainable credentials, Maclennan co-founded CLASS, a unique initiative created for those in search of sustainable textiles for the fashion industry.