
I have some horse butt for the next one. It's preferred for belts you wear because it doesn't stretch much.
I have noticed that many top bow saddles and other straps seem to be made from chrome-tanned leathers which do not weather well. They tend to fry like bacon in the hot summer sun, and shrink a lot. Oak-tanned leather lasts better, I believe, especially if treated occasionally with saddle oil. Ray Holes saddle butter is an excellent treatment for leather exposed to the elements, if you can find it.
Last, if you make these accessory items from oak tanned leather, you can "dye" them black with an iron acetate solution. It turns the leather black, but will not come off on your hands or clothing. Simply steep some steel wool or clean nails or bolts in vinegar for a few days, and apply.