Stable, concentrated, aqueous solutions of basic oxazine dyestuffs of the formula IN WHICH R'' and R'''' represent lower alkyl groups, R1 and R2 represent hydrogen atoms or lower alkyl groups or phenyl unsubstituted or substituted in the benzene nucleus by methyl, methoxy or ethoxy groups, R3 represents hydrogen or methyl, and X represents a halogen ion, consisting essentially of (a) the hydrochlorides of the said oxazine dyestuffs and (b) high molecular polyglycols in an amount of about 2 to about 20 percent by weight calculated on the weight of the dyestuff.