For the second consecutive month, a leading index reported an increase in North American containerboard pricing. Month-over-month containerboard prices rose $30 per ton in April, following March’s $40 per ton increase, according to monthly data released Friday in Fastmarkets RISI’s Pulp & Paper Week publication. When also taking into consideration the $20 per ton decrease the index reported in February, containerboard pricing has a year-to-date net increase of $50 per ton. …On the boxboard front, most prices remained relatively flat in April. Solid bleached sulfate remains in oversupply, although demand was flat to slightly improved.