Clare Johnston won the RSA Textile Prize in 1972. In 1975 Clare launched the Veronica Marsh textile design collection in Paris, successfully establishing business with many fashion companies.

In 1995 Marks and Spencer’s £1 billion record profit was partially attributed to the customers' favourable response to the colour products on offer in store developed by Clare Johnston and the M&S design team.

As chair of the Textile Institute's Design Special Interest Group since 2006, Clare Johnston has directed the annual Treasury Fashion and Textile Showcase exhibiting a selection of UK graduates' work to industry and government.

In 2007 Clare Johnston was awarded the Society of Dyers and Colourists Silver Medal for her contribution to the use of colour in education.