He can't proof anything with a photo.
The reason for it is very simple.
Design a shaped sail using basic 2D cloth by a method called broad seaming. But instead of having a single layer of cloth with stitched overlaps on the edges (= seams), make it out of multiple layers, 2 or 3. When designing these shaped panels make sure that the panels that belong to a given layer have "egdes" (if we may not call them seams) that are shifted relative to the edges in the layers above and below it.
Get a 3D workbench (like a model airplane wing) and lay the first layer of panels with their egdes butt to butt and lay the second layer of panels, the ones with their egdes in different locations, on top of the first and also butt to butt. Glue the pack together. Repeat this for every new layer.
Basically, the small (stitched or glued) overlaps that most of us would easily recognize as "seams" are now transformed in very broad overlaps that most people won't recognize as easily as "seams". The lack of stitching because glue was used reinforces this impression. The irony of course is that the name "BROAD seaming" is probably more decribtive of this new layup then it was for the old way of joning panels. But that is a side track. Of course to improve load bearing properties a maze of fibres is glued between some layers, introducing all kinds of small lines running in every direction hiding the splits between the monofilm panels; but that is not important in the shaping part of the analysis.
Of course forcing these curved egdes of the panels to REMAIN back to back is what is shaping the sail when it is removed from the mould (3D workbench). These transitions from one panel to the next inside a single layer are the "seams" of the 3DL sail. They force shape into the sail in exactly the same way as "broad seaming" and therefor it is "broad seaming".
Everybody can try this himself at home using pieces of paper or plastic bags and glue or BROAD duct tape. I made shaped stunt and power kites that way as far as 25 years ago.
Of course promotors and other persons who are not too smart will now claim to have pioneered a totally new shaping proces that is completely different to broad seaming. Their proof ? Just asking anybody to point out the "seams" in a photograph.
Guys, this is all pretty old news. Even sailing magazine articles as old as 2004 have described it in similar terms :
http://www.sailingworld.com/sailing-gear/sails/changes-in-racing-sails-and-sailmaking-33336.htmland I quote :
North's rivals say that the edges of the Mylar panels are cut on a curve to match the shape of the mold, making the sails no different from others except that they're laminated atop a three-dimensional work bench, i.e. the mold. It's true that North's panels are cut on a curve to lie smoothly on top of the mold. After being cut, the pieces are butted against each other and taped with a wide swath of cellophane-type tape before load-bearing fibers and a tear-preventing scrim (also pre-shaped) are laid down.
Model airplane builders have been using such techniques for decades before North Sails gave it a fancy name.
Why is everybody falling every single time for the debating techniques of Macca where he is arguing the impossible ?
Wouter
