A male touch fastener strip includes an elongated base having a thickness and defining a longitudinal direction and a lateral direction perpendicular to the longitudinal direction across the base between longitudinal edges of the base, and a field of male fastener elements each having a stem extending from a broad face of the base and a head at an upper end of the stem and overhanging the base for engaging fibers. The fastener element stems and broad face of the base together form a unitary mass of resin. The male touch fastener strip also includes a pair of longitudinal barrier walls rising from the broad face of the base on either side of the field of male fastener elements, and a plurality of lateral barrier walls. Each of the lateral barrier walls extends between facing surfaces of the longitudinal barrier walls to define a longitudinal column of bounded fastening cells that each contain one or more male fastener elements. Each lateral barrier wall defines at least one gap extending therethrough and connecting adjacent fastening cells.