25 8 11 81 0 nabh sub 4 di 1370 17 4 15 61 0 nabh sub 4 11 2 ppm ca 1030 32 7 26 2______________________________________ di deionized water of all the samples listed in table 1 only those samples showing statistically significant improvement over the untreated unwashed control papers are included in tables 3 and 4 as shown in table 3 all of the samples showing significant improvement in brightness retention had been washed with 11 2 ppm calcium the 1 0 percent nabh 4 treated samples showed significantly greater improvement in brightness retention than that conferred by calcium washing alone as shown in table 4 a 1 0 percent nabh 4 solution treatment followed by 11 2 ppm ca wash shows 25 to 30 times the folding endurance stability of the control and 4 times the stability of a ca wash alone also both 0 1 percent nabh 4 treatment without a wash and a 1 0 percent nabh 4 treatment with a deionized water wash showed significant improvement newsprint paper from a single roll was cut into 8 34 by 10 34 machine long sheets the newsprint was made from about 80 percent groundwood and 20 percent unbleached sulfite pulp newsprint sheets were treated and aged and physical and chemical properties measured as specified in example 1 table 5 lists the initial physical and chemical properties conferred to the experimental newsprint papers by the various treatment and or washing procedures for newsprint the borohydride treatment produced increases in initial handsheet brightness of up to 10 brightness units the decrease in brightness observed on calcium washing is typical of newsprint but the combination of either 0 1 percent or.