Speaking of rigid parrels, this video clip from Steve D (Serenity) just came on Facebook today. https://www.facebook.com/share/v/1KR6WMqei3/

A sail with a planform which defies the rules of yard-angle/rig-balance yet sets perfectly, not a wrinkle, under halyard and mainsheet only. Rigid parrels do the rest. Nothing to adjust when reefing (except the halyard and the mainsheet).

History.  The origin of the rigid parrel goes back to around 2014 with the aerojunk (with its double wishbone) and the wingsail (with it's skeletal structure) which, in effect, do each amount to a form of rigid parrel to the mast. Then the "D-former" of Paul McK (see Feb 2021 magazine), which gave rise to the variant used here by Steve (July 2025 magazine), all based on the desire for a "symmetric" (same on both tacks) lug sail. And then came the asymmetric "pistol parrel" of Jan Cz. (see forum thread sorting out my parrels 10 November 2025) Then, more recently, Arne drew a refined version of an asymmetric rigid parrel, unpublished, which has not yet been tried. 

(By the way, note the slings which go underneath the sail catcher, which transfer the weight of the sail bundle to the lifts - without putting any load on the sail-catcher's skeleton. That's the way to do it. Steve has got things pretty tidy).