Artist Reply: Thanks marie-claire..Reinforcement Bars Are Key To Strength & Longevity..We Bend Thin Sheet Metal To Match A Rubbing Of The Leaded Lines & Solder It At Each Joint To Affix..It Is Then Painted Gray To Match The Lead & Held Firm By The Frames Wooden Stop..This Panel Will Not Bow To Gravity Or Hearty Door Closings..This Technique Is Used On All Of Our Leaded Panels Seen In The Portfolio