I am going to make a leather back quiver. I have a design in mind, but I have been looking at some of the quivers posted here and notice many of them have a window on the lower 1/3 of the quiver.

Is this for any particular reason other than for looks?

Thanks,
Jethro

That is where you take your arrows out from and also load them back in.Its a neet system.

The quivers with the "windows" are side quivers, meant to be worn on the side, not on the back.

well i made some like your describing, and it hangs on my back. you pull the arrows out from the hole near your hip. on mine i made the top removable to load the arrows easier and not ruin the fletching.
can't say for sure all the reasons, but it keeps the arrows from falling out no matter how you have the quiver. it keeps the fletching from catching on anything. keeps the fletching dry in the rain or snow. for some it may be easier to remove the arrow that way, and less movement than reaching over your shoulder. good luck with your project  

hunterace, can you send me any pics?

Thanks,
Jethro

There many different back quivers and side models. The each have advantages and disadvantages, depending on what you like.

Personally, I like the Hill style, and I have made or bought the St. Charles, Safari, and CatQuiver.  You might start by searching online for quivers sold by custom makers, as advertised in magazines and this website. Collect a few catalogs, like 3Rivers and Kustom King. Find a shop or Trad shooter in your neck of the woods and see what they like for the type of hunting you might do.

A carpenter's rule is measure twice and cut once.

This is what I use and make. Picture is not great but you get the idea and it is a back quiver you just wear it on the other side and just reach , lift and drop your arrow out.

Rick