Positively encaging. No, that’s not a typo. It’s the charming theme Jean Paul Gaultier proposed in his fall couture collection, one built around the cage. And he worked it to such fabulous effect that any woman would love to be caught in one of his inventive creations. The motif succeeded for a simple reason: Gaultier himself never got stuck there. Unlike some past thematic conceits that ultimately trumped his fashion, this one provided not only editorial oomph but ample design inspiration, as well. It started with the designer’s impeccable tailoring. He kept it razor-sharp and reed-thin, diversifying suit after suit with cage allusions that put much of the emphasis on the waist. One, in double-faced wool, defined the torso with rows of tautly buckled straps; another, in black, featured trellis work as a window onto a shimmery silver top.Yet the suits were just part of the story. The cage shtick manifested in myriad ways, some 3-D structures, others, gentle whispers of lace. There were strappy riding pieces that winked at bygone bondage; an Aran knit dress, split open and stiffened; a jeweled silver leather grid encasing a mink coat. And there was relief from all the openwork in winning classics as a shiny black cocktail dress and superlative new takes on the trench. Gaultier is sure to get lots of hits with his web sight.