  We present the NLO QCD corrections to diphoton plus jet production at hadron
colliders. Our calculation includes contributions from the fragmentation of a
hadronic jet into a highly energetic photon, and consequently allows the
implementation of arbitrary infrared-safe photon isolation definitions. We
compare different photon isolation criteria and perform a detailed study of the
dependence of the diphoton plus jet cross section on the photon isolation
parameters.
