Folding and boudinage are NOT characteristics of contractional and extensional tectonics respectively. Both types of structure can be found in any tectonic regimes. In fact boudinage can be the consequence of folding, as shown by the picture on the right.

Photo on top: Folding and boudinage (Montagne Noire, France, Photo credit: P. Rey).
Photo at bottom: Folds and boudinage in ore body, the picture is ca. 8 cm long (Mt Isa, Queensland, Photo credit: P. Rey)