A security device, such as a security thread, uses multiple security detection features provided by combining metal and metal/magnetic security features on a carrier substrate. The security detection features basically comprise an optionally repeating pattern of discrete metal/magnetic indicia and discrete metal or metal-dot formed indicia. The security detection features may also include at least one metal strip extending along the length of the carrier substrate and/or a plurality of metal dots located on metal-free portions of at least one surface of the substrate.