I just got into blowguns seriously. I grew up on a river bank and loved ninja movies... so I had made blowguns and bought the 36" flea market/pawn shop .40 calibers.
I have been studying the forum here and Youtube like I did 4 or so years when I seriously got into slingshots. And about 12 or so years ago I found the Slingshot Channel by Jorg Sprave. This time I found The Blowgun Channel and @Lobohunter 's videos. John on the Blowgun Channel has a video on this card sight.
The lanyard is to help me secure the pipe because my left hand is weakened due to a pinched nerve. I secured it with a leather tong using clove hitches and single overhand knots.
I cannot exactly see the shadow "V" image that is described, but I see the right side of this card sight just left if the target. I made a mock up with cardboard and sharpie marks. However when the lighting is poor I couldn't see the marks. The kydex is more sturdy and allowed for notches which are highly visible in poor lighting.
Any tips or comments or what-have-yous will be appreciated.