An investment mold includes a mold cavity and a refractory investment wall that bounds at least a portion of the mold cavity. At least a portion of the refractory investment wall includes a plurality of fugitive beads. The fugitive beads can be sacrificed to provide voids that control the strength of the refractory investment wall such that the wall fractures at the voids during investment casting to alleviate stress on a solidified metal cast in the mold cavity.