Prima Finnabair - Decorative Chipboard - Mechanical Thistle £5.99 Quantity: at £5.99 each Add To Basket Finnabair's 1st release of chipboards, at 2mm thick they are great for making mixed-media compositions. Sheet size: 20 cm. x 20 cm. (8'' x 8'') approx. Use with paints, sprays, embossing powders and more.