I have only built one osage selfbow so far. but I was wondering if I can cut a sight window into my next one.  If I do this do I take a chance of it breaking in half? or would it help to back it with leather?  I hope that someone out there can help me.  Thanks, Tony  

Cutting in a sight window is always a risk with any bow. Just don't leave any less than 3/4". Sight windows (closer to center shot) do make a bow easier to tune.

I would rather design my bow (lay out the center line) so the string lays off center a little. Left of center for righthanded shooter. Then just use a floppy rest.

what do you mean by a flappy rest?  One of the stick on rests?

No, he means a soft piece of leather, elk is used a lot, folded onto it's self (doubled) and glued on so the fold is sticking out over your bow hand.  Lay the arrow on that and shoot.  Look up Ferret's instructions on the How To Resources thread on this site.
I've seen pictures of sight windows on self bows that look great but there is always a risk of a break.  Osage and other hardwoods would probably be the best choice for that.

this is the window from a board bow I just finished.

Arrow shelf would be more the term. Unless you are gun barreling the arrow you can't see thru it anyway.Personally, I think selfbows look silly with arrow shelves cut in, but that's just me, your wants and wishes are different.Just don't get caught up in the trap that it needs a shelf to shoot good or that the shelf will cure any tuning problems. I fear we sometimes like to fall into the "glass bow trap" when it comes to selfbows, trying to re-invent the wheel so to speak.

Having a shelf on a selfbow doesn't mean you have to hack out the handle/fade area.  Just leave some wood in the handle where a shelf would be and then when you are shaping the handle carve out the rest area.  I cut shelves in all mine and haven't broke one yet.  But I've only made 7 or 8.  I try to cut in to about 1/4" from center to give me a little more leeway on arrow spine.  This doesn't eliminate tuning but helps out.  I just don't see the point in taking all the wood away at the handle then going back and gluing leather back on to form a rest.  But like Flinttim said, it's a personal preference.  Different strokes for different folks!  If you do cut a shelf in close to center, just leave more wood on the other side of the handle to compensate.

Aaron

I have been cutting in a small 1/8-3/16" shelf and glueing a piece of 7/8 oz vegetable tanned leather beside it.  I shape the leather when I am dressing up the shelf.  I get the size shelf I want without cutting it all out of the side of the bow.  

thanks guys for all of your help. I guess as I build this next osage bow I will do a little experimenting.