The genus of an element in the commutator subgroup of a group \(G\) is the minimal number of commutators of which the element is a product. It has been shown previously that in a free group each element of genus \(n\) can be obtained by permutation and suitable substitution on one of a finite number of words called orientable forms of genus \(n\). In the present paper this is generalized for free products \(G\) of arbitrary groups: again any element of genus \(n\) can be obtained by a permissable substitution from an orientable genus \(n\) form over the free product defined in a suitable way using circuits in cubic graphs. At the end of the paper, a list of all non-equivalent orientable genus two forms over free products is given.