Guitar sheets
A guitar sheet is a smooth polymer sheet of greater thickness and area, named after the chocolate guitar — a strung frame used to cut ganache and praliné into even squares.
What separates it from ordinary acetate strip is format and rigidity: it is a large sheet rather than a band, and it stays flat. Confectionery mixtures are cast in a frame between two sheets, left to stabilise and cut directly on the lower one.
The surface matters. Ganache set against a guitar sheet takes on a glossy flat face that shows in the finished bonbon — which is why the sheets are protected from scratches and never scrubbed.
A separate use is textured sheets with an embossed pattern: chocolate decorations are cast on them and take the impression. This is how structured bars, decorative bands and bonbon bases are made.