Low temperature co-fired ceramic (LTCC) is the favored manufacturing technology for millimeter-wave substrate integrated waveguide (SIW) systems. SIW consumes a significant quantity of LTCC conductor material, typically gold or silver, as the width of substrate integrated waveguide is set according to the TE10 mode cut-off frequency. However, the solid conductors forming the top (and bottom) walls of SIW can be replaced by a conducting mesh thereby reducing the amount of precious metals required. Both simulations and experiment of SIWs operating at X-band demonstrate the feasibility of using a meshed conductor. The mesh does not significantly increase passband insertion loss.