International Paper , North America's second largest uncoated freesheet paper producer, announced a $60 price increase for its Williamsburg offset roll, return postcard rolls, and end leaf papers, the company said in a Mar. 2 letter to merchant customers. The increase is effective Apr. 1. Both IP and Domtar, the two largest North American UFS producers, now plan increases for Apr. 1 in what is the first increase in UFS pricing in the USA in more than two years.