So, I had a few raindrops hit an oage bow I had in the bback of my truck. When it dried it left a ring. The center was lighter color than the osage that didnt get wet. Round the outside edge of the water ring it was darker than any other area. It seems water pics up the color in osage, and as if dries, pushes it to the outside of the water drop, robbing the inside of its color.
Well, when you do it intentionally, boy it comes out looking like copperhead. I gadda work on my technique but this is a neat way to ghost a copperhead pattern on an osage bow. I have done it in the daylight, seems to work better leaving a better edge around the drop as opposed to nights where it takes so long to dry it seems to pull the color line inwards instead of outwards.
All you do is draw with water, making sure the drop stands proud on the limb. Im thinking white or clear wax could be used to guide the drop and keep it '" inside the lines ".