I recently acquired a clear Exactra 20! I liked how the frosted one looks on my Obi, and my ANH graflex has never had a real bubble strip!
looking at the clear one it just seems...quick and dirty logical that they'd use the pinch method. The little rectangle surrounding the bubbles is the exact area between a closed clamp. Also, the exactra being skinnier than the full width inside the clamp (ESB cards) reinforced this idea. I felt horrible cutting up the lens though, grumble grumble vintage parts
looking at the clear one it just seems...quick and dirty logical that they'd use the pinch method. The little rectangle surrounding the bubbles is the exact area between a closed clamp. Also, the exactra being skinnier than the full width inside the clamp (ESB cards) reinforced this idea. I felt horrible cutting up the lens though, grumble grumble vintage parts