<p>A method for treating a cellulosic material comprising extracting the cellulosic material with an extractant to selectively extract hemicellulose therein and separating the extracted hemicellulose to form a cellulosic product comprising less hemicellulose than the cellulose-containing material. The extractant comprises an ionic liquid and a non-solvent. The cellulosic product retains the cellulosic fiber morphology.</p>
