Abstract: The present invention is a wall cap corner aid, in particular for use with stucco and/or plaster. The preferred embodiment of the invention is made from a metal lattice structure, preferably metal lath. The wall cap corner aid has a first leg joined to a concave center span at a metal edge corner. The corner is a discontinuity in the metal lattice structure made of smooth metal. A second leg is joined to the concave center span at a second smooth metal edge corner. Furthermore, the legs are preferably flexibly biased towards one another for mounting onto a base such as wall cap or a railing.