A set of iron-type golf clubs includes long irons with channel back configurations and short irons with cavity back configurations. The rear face configurations transition from channel backs through to pure cavity backs for increased performance continuum for the set. Additional design parameters for the set may also be systematically varied through the set, such as groove type and depth, loft angle, cavity volume, hitting face roughness, and sole width. At least one of the clubs of the set includes a sandwich-type construction for the hitting face having a dampening element disposed between a hitting face insert and a lightweight reinforcing core. In one embodiment, at least one club head is oversized.