Final answer:
Paul Poiret is the Parisian designer credited with liberating women from corsets and for advancing the draping technique in fashion design, reflecting a broader movement towards comfort in women's attire that became prominent after World War I.
Step-by-step explanation:
The Parisian designer known for freeing women from corsets and pioneering the use of the draping technique in dressmaking is Paul Poiret. Poiret's radical approach to fashion design in the early 20th century was characterized by the elimination of corsets from women's attire, in favor of much more comfortable, flowing garments. His work was a key contributing factor to the evolution of women's fashion during an era that was increasingly prioritizing comfort, as well as aesthetic appeal. Poiret's influence is reflective of broader social changes that took place in the post-World War I period, including the rise of the 'flapper' style, which represented a significant break from past fashion norms in favor of simpler, more practical attire that allowed for greater movement and freedom.