Cold sintered composites of xBF12-(1-x)LMO offer several advantages over there conventionally sintered counterparts. Cold sintering is a more efficient processing route for the fabrication of composites, reducing the energy consumed by approximately 50% with a commensurate reduction in CO2 emissions. In addition, densification is achieved comparatively easily which is not the case for conventionally sintered composites. Most crucially, the negligible interaction between the end members results in only a limited decrease in Qf despite the addition of 15 wt% BF12, unlike during conventional sintering where interaction causes a catastrophicdeterioration in properties [33,34]. Guo et al. [13] compared cold with conventionally sintered LMO. They reported that cold sintered LMO showed superior εr (5.6 against 5.5) but lower Qf (30,500 against 45,000 GHz) than conventionally sintered ceramics [13]. One further advantage often overlooked, is that the lateral dimensions in cold sintering are precisely confined to the width of the die, i.e there is zero lateral shrinkage. This reduces the need for extensive post-sinter machining of parts to tune their dielectric properties. This latter advantage is important for the fabrication of low cost RF substrates and devices and could, coupled with the low densification temperature, revolutionize the manufacturing of ceramics in RF devices.