The brand is unveiling a new look in December as part of a move to promote its all-natural cheese credentials, a move that will be promoted with a £5m marketing campaign. Purple packaging, a "softer, more natural" logo and a revamped Mr Strings character are among the packaging changes.
Packs will also make more of the fact that every Cheestring is made with 100%-natural cheese and a full glass of fresh milk, which provides 26% of the RDA of calcium for a child aged five to 10.
The campaign will include a new set of TV adverts, which will air for the first time in January.
The brand, which has grown 26% in value in the last 12 weeks and 8% year-on-year, currently accounts for 31% of the kids' cheese snacks category.