Abstract: An inexpensive, easily produced device is provided for insertion between layers of wooden boards, which device has sufficient resistivity against longitudinally directed stresses, sufficient frictional engagement with the wooden boards, and sufficient ease of insertion, that the device may be advantageously utilized with piles of boards to prevent the piles from falling apart during handling. The device comprises a longitudinally enlongated strip of stiff cellulosic material having a predetermined constant width and formed by a pair of adhesively secured layers over the majority of the width thereof, and defining a plane. A pair of longitudinally elongated projections, one disposed on either lateral edge of the strip, and formed from at least one of the layers of stiff cellulosic material, stands upright from the plane of the strip substantially the entire length of the strip.