### Flasque model structures for simplicial presheaves , by Daniel C. Isaksen

By now it is well known that there are two useful (objectwise or local)
families of model structures on presheaves: the injective and projective.
In fact, there is at least one more: the flasque. For some purposes,
both the projective and the injective structure run into technical
and annoying (but surmountable) difficulties for different reasons.
The flasque model structure, which possesses a combination of the
convenient properties of both structures, sometimes avoids these
difficulties.

Daniel C. Isaksen <isaksen@math.wayne.edu >