The revamped look, by branding agency Jones Knowles Ritchie, features a softer purple logo and a toned-town 'Mr Strings' character, as Kerry Foods attempts to make the product seem less artificial.
Packs will aim to communicate facts about the snack, such as each Cheestring containing a glass of milk. Each individual wrapper will depict a different character illustration and 'fun fact'. The range comes in Original Cheddar, Twister, White Cheddar and Light variants.
The rebranding will be supported by a £5m integrated campaign, including several TV executions, which will be rolled out next year.
Ad agency Fallon was awarded the Cheestrings advertising business in May, while two months ago, Vizeum scooped its £13m media planning and buying account for the UK and Ireland.
With claimed annual sales of about £50m, Cheestrings accounts for 31% of the children's cheese snacks market. The brand was launched in 1996 and last underwent an overhaul in February 2006, when Kerry Foods invested £5m in a campaign to overcome misconceptions that it is not 100% cheese.