When purchasing from a Graphene Powder Factory, you must prioritize the Specific Surface Area (SSA), typically ranging from 50 to 1000 m²/g, and the number of layers, as 'few-layer graphene' (3-10 layers) offers different conductivity than 'multi-layer' variants. Ensure the purity level is ≥98% to avoid residual surfactants or graphite. Additionally, verify the lateral size (D50) and oxygen content, as high oxygen levels indicate Graphene Oxide (GO) rather than pure Graphene (rGO/GNP), which significantly impacts electrical and thermal conductivity.