an acid concentration of from about 5 to about 25 by weight preferably from about 8 to 25 by weight is required in the fabric softening composition the acid used may be an organic or mineral acid the organic acids are preferably saturated or unsaturated c 2 c 6 carboxylic acids such as citric acid formic acid maleic acid tartaric acid and succinic acid citric acid malonic acid and maleic acid are particularly preferred a mineral acid such as hcl which is particularly effective to protonate the diester amine softening compound may be advantageously combined with such organic acid generally the concentration of mineral acid should not exceed about 5 preferably not more than 2 by weight of the fabric conditioning composition so as to prevent unwanted product separation a carboxylic acid may then be used to supplement the mineral acid up to a total acid content of about 25 without adversely affecting product stability an optional fabric conditioning ingredient is a fatty alcohol wherein the hydrophobic group may be a straight or branched chain alkyl or alkenyl group having from about 10 to 24 preferably from about 10 to 20 especially preferably from about 12 to 20 carbon atoms specific examples of the fatty alcohol include decanol dodecanol tetradecanol pentadecanol hexadecanol octadecanol lauryl alcohol palmityl alcohol stearyl alcohol oleyl alcohol and mixtures thereof furthermore the fatty alcohol may be of natural or synthetic origin and my include for example mixed alcohol such as c 16 c 18 alcohols prepared by ziegler polymerization of ethylene the fatty alcohol may be present in the composition in a minor amount relative to the cationic fabric softener such that the ratio by weight of the cationic fabric softener to fatty alcohol is in the range.