Rolling or flipping boards are very long, thin boards with bevelled edges to allow you to move your delicate, thin-skinned, risen baguette dough from your couche and then onto your peel without tearing the dough and deflating it.
When your dough is proving on a couche, side-by-side with other baguettes or batards, with folds of the couche to separate them, moving them without disturbing them can be tricky. Using a rolling board makes this straightforward, although there is of course a technique:
Taking the outermost baguette, drop the outside edge of the couche linen, making it flat on the table. Use this excess couche to roll or flip the baguette onto the board which is held along the baguette, between it and the next one. Gently lifting the excess cloth will cause the baguette to roll onto the board. From there it may then be flipped again onto the peel and from there slid into the oven.
This rolling or flipping board (also known as a planche à couche and planchette) is made from beech which is a wood suitable for contact with food, and measures 60cm long, 10cm wide and 0.5cm thick.