Cotton rags of the qualities termed in the trade "new" and "old" were used in making the papers. New rags are cuttings from unused textiles and come largely from textile and garment factories, whereas old rags are used textile materials, and are principally waste products from homes. The rags employed were the grades known commercially as no. 1 white short cuttings, unbleached hosiery clippings, unbleached muslin, unbleached shoe cuttings, twos and blues, and no. 1 old whites. They were supplied by a commercial paper mill and had been sorted, cut, and dusted. The rags were purchased as being representative of the respective grades. Analyses reported elsewhere herein of the various kinds of rags before they were submitted to the paper-making processes and also after they had been boiled, washed, and drawn out of weave (reduced to half-stuff) indicate the degree of cellulosic purity of the fiber and the extent to which the cellulose had been modified or degraded either in preliminary treatment or in actual preparation of the half-stuff. The rag composition of the beater furnish, that is, the various kinds of half-stuff blended in the beater, is included in the data for each of the paper-machine runs.