  We present the results of a new model calculation of the gamma-ray background
produced by unresolved blazars, using the second EGRET catalogue and taking
account of flaring. These results are compared to the preliminary gamma-ray
background spectrum reported recently by the EGRET team. We find that blazars
can account for the entire extragalactic gamma-ray background observed by
EGRET. In addition, the EGRET spectrum shows some evidence of a signature for
the blazar background, in the form of a concavity in the spectrum.
