The full text of the letter follows:January 11, 2012 To the Board of Directors, Starboard Value LP, together with its affiliates, currently owns 9.3% of the outstanding common stock of Wausau Paper Corp. (" Wausau" or the "Company"), making us the Company's largest shareholder. We have sent the Board two detailed letters, one on July 28, 2011 and one on October 3, 2011, outlining our views and perspectives on (i) the opportunities that exist to significantly improve the value of the Company and (ii) Board composition and corporate strategy. We have reviewed the Company's third quarter earnings results, as well as recent announcements regarding (i) the sale of the Company's remaining timberland assets, (ii) the sale of the Print & Color brands (part of the Company's Paper segment) and (iii) the Company's plan to permanently shut down its Brokaw, Wisconsin mill. While these initiatives represent a step in the right direction, we believe the Company remains meaningfully undervalued and that there is still much more that can be done at this time to unlock significant value at Wausau. The Evaluation of Strategic Alternatives Should Be Expanded Beyond Just the Print & Color Brands We are encouraged by the Company's announcement that it has sold its Print & Color brands and will be closing the Brokaw mill. As we have highlighted, the Company's Print & Color franchise was losing a significant amount of money and repeated attempts to fix this business had failed. While we clearly support the decision to sell this business, Wausau's evaluation of strategic alternatives should not end there. Instead, the strategic review should be expanded to include a potential sale of the remaining Specialty Products portion of the Paper segment, as well as a sale of the entire Company. Without expanding the scope of the strategic alternatives review, the Board is not giving itself the opportunity to fully evaluate all options that could enhance shareholder value. To that end, we would encourage the Board to promptly retain a reputable financial advisor to evaluate all alternatives to maximize value, including a potential sale of the Paper segment or the entire Company. In case there is any doubt from the Board whether a sale process could generate sufficient interest in a transaction at this time, it is our understanding that numerous potential buyers have previously expressed a desire to acquire the Tissue business or the entire Company, but that the Company has not been willing to engage in discussions in furtherance of a negotiated transaction.