A control apparatus is disclosed for controlling nip pressure in a nip of a metering size press. The apparatus includes a metering size press roll and a backing roll which cooperates with the size press roll for defining therebetween the nip. A support post is provided for rotatably supporting the backing roll. A linear bearing is disposed beneath the support post for mounting the support post. Also, a moving device is connected to the support post for moving the support post and the backing roll supported by the support post such that the supported backing roll and the support post mounted on the linear bearing is moved for controlling the nip pressure in the nip between the rolls.