  In this paper, we present a new lower bound on the size of separating hash
families of type {w_1^{q-1},w_2} where w_1 < w_2. Our result extends the paper
by Guo et al. on binary frameproof codes. This bound compares well against
known general bounds, and is especially useful when trying to bound the size of
strong separating hash families. We also show that our new bound is tight by
constructing hash families that meet the new bound with equality.
