Abstract: Dyestuffs of the formulaeD--Z--O--OC--X--O).sub.y H].sub.nandD--Z--O--OC--X--O).sub.(y.sub.-1) COT].sub.nwherein D is the radical of an anthraquinone dyestuff which is attached to Z through a carbon atom of an aromatic ring present in D; Z is a divalent bridging group; n is a positive integer having a value of 1 to 4; X is a divalent saturated or unsaturated aliphatic radical containing at least 8 carbon atoms and in which there are at least 4 carbon atoms between the --CO-- and --O-- groups; T is a saturated or unsaturated aliphatic radical of from 8-20 carbon atoms and y is a positive number in the range 2-20 inclusive.A process for making the above dyestuffs and their use as dispersing agents in the stabilization of dispersions of finely divided solids.