Fiberglass for bow making is pretty expensive stuff. From what I know it's pretty much Bearpaw rolls, and Gordon's Bo-tuff strips. A friend of mine uses Bearpaw rolls. I haven't done the maths but I imagine its cheaper to buy a roll if you are going to make a lot of bows. If you just want to experiment, then buying cut strips is probably a better option, and you can also buy strips of different thickness.
There might be a cheaper Asian product, that Chinese, and Korean manufacturers use, though I am not aware of a brand.
