The invention relates to mixtures of cellulose ethers, comprising A) allyl-modified cellulose ethers of formula (1) where C.sub.6H.sub.7O.sub.2 is one anhydroglucose unit, n is from 50 to 1600, R.sup.1, R.sup.2 and R.sup.3 independently of one another are a polyalkylene oxide chain of the formula (2), with X=H, CH.sub.3, C.sub.2H.sub.5 or CH.sub.2CH.dbd.CH.sub.2 and in which p, q and r independently of one another, in R.sup.1, R.sup.2 and R.sup.3 each independently, can adopt values from 0 to 4, the sum (p+q+r) added over R.sup.1, R.sup.2 and R.sup.3 per anhydroglucose unit is on average more than 1.3 and less than 4.5, the sequence of the oxyalkyl units in the polyalkylene oxide chain is arbitrary and the average number of --CH.sub.2CH.dbd.CH.sub.2-- groups per anhydroglucose unit is from 0.01 to 0.1, and B) cellulose ethers of formula (3) where C.sub.6H.sub.7O.sub.2 is one anhydroglucose unit, n is from 50 to 1600, R.sup.4, R.sup.5 and R.sup.6 independently of one another are a polyalkylene oxide chain of formula (4) where Y=H, CH.sub.3 or C.sub.2H.sub.5 and in which p, q and r independently of one another, in R.sup.4, R.sup.5 and R.sup.6 each independently, can adopt values of 0 to 4, the sum (p+q+r) added over R.sup.4, R.sup.5 and R.sup.6 per anhydroglucose unit is on average more than 1.3 and less than 4.5, and the sequence of the oxyalkyl units in the polyalkylene oxide chain is arbitrary, in an A:B mixing ratio of from 1:99 to 99:1 by weight.