The appellant, Minneapolis Star & Tribune Co., 'Star Tribune,' (P) is the publisher of a morning newspaper and an evening newspaper. It enjoyed an exemption from the sales and use tax provided by Minnesota for periodic publications. The legislature then amended the scheme to impose a 'use tax' on the cost of paper and ink products consumed in the production of a publication. The legislature again amended the statute, this time to exempt the first $100,000 worth of ink and paper consumed by a publication in any calendar year, in effect giving each publication an annual tax credit of $4,000. After the enactment of the $100,000 exemption, 11 publishers, producing 14 of the 388 paid circulation newspapers in the State, incurred a tax liability in 1974. Star Tribune was one of the 11. Star Tribune instituted this action to seek a refund of the use taxes it paid from January 1, 1974, to May 31, 1975. It challenged the imposition of the use tax on ink and paper used in publications as a violation of the guarantees of freedom of the press and equal protection in the First and Fourteenth Amendments. The Minnesota Supreme Court upheld the tax against the federal constitutional challenge.