After settling, the clear solution containing the titanium oxide, is run oil andfurther processed, whereby a roduct is obtained containing approximate y 35 per cent titanium oxide, 2 per cent sulphuric acid and 63 per cent of water. This product is known in the trade as titanium acid cake. It is a plastic mags having somewhat the consistency of mu 1 ljha've discovered that lithopone can be greatly improved by the suitable use of this titanium acid cake, and that the results obtained are dependent to a large extent upon the methods'by which this titanium acid cake is used,'in the production of lithopone.