Methods for forming images are disclosed. The images are formed by imaging and developing an imageable element comprising a layer of an imageable composition over a substrate. The imageable composition contains a polymeric binder, an acid activatable crosslinking agent, and an acid generator of the structure: in which: Y is hydrogen, halo, alkyl, diphenylamino, phenylthio, or (CH2)kSO3− in which k is 1 to 4; R1, R2, R3, and R4, are each independently hydrogen or SO3− with the proviso that the anion has two to four SO3− groups; Z1 and Z2 are each independently a benzo group or a naphtho group; Z3 is two hydrogen atoms, a cyclohexene residue or a cyclopentene residue; X1 and X2 are each independently S, O, NH, CH2, or CMe2; Q⊕ is an onium cation; n is 1 to 4; and m is 1 to 3, with the proviso that m is 1 when the anion has two SO3− groups; m is 2 when the anion has three SO3− groups; and m is 3 when the anion has four SO3− groups.