When sourcing anti-magnetic materials, you must prioritize Magnetic Permeability (μ); for high-shielding efficiency, look for materials with high initial and maximum permeability like Mu-Metal (Nickel-Iron alloys). Additionally, verify the Saturation Induction (Bs) to ensure the material doesn't lose its shielding properties in strong magnetic fields. For structural applications, consider Austenitic Stainless Steel (300 series) or Aluminum alloys, which offer low magnetic susceptibility while maintaining mechanical strength.