It has become apparent during the last few years that some important aspects of rock magnetism require data that can not be provided by studies of natural Fe-Ti oxides. Accordingly, there have been efforts by several groups to develop techniques to produce synthetic materials suitable for the required studies. This paper presents the preliminary results of an attempt to grow oxides of the magnetite-ulvospinel series using the flux growth technique with a NaBO4 flux. I focus here on the essential first step in the process, which is the establishment of the temperature and oxygen fugacity conditions necessary to grow the desired phases. The results show that the Fe-Ti-B-O system is complicated by the presence of borate phases as well as the expected oxides. The net effect is to place an upper limit on the ulvospinel concentration that can be achieved which varies with temperature from about 10% at 1200 ¿C to around 60% at 1000 ¿C. ¿ American Geophysical Union 1988