Mine is backed with black silk, applied with Titebond. It isn't smooth, and it certainly isn't pretty. It stacks all I can pull just about the corner of my mouth, drawn two under. It throws a heavy arrow pretty good, although it is nothing in the speed department, but then, it has never had a good string on it either.
Oddly enough, the grain is almost perfectly straight in mine, in each end of the bow. On one end, it is straight like you would orient a self bow, and on the other, it is almost perfectly straight, with the grain ending in the back and belly. It twists through the handle area, but that is also a working part of the bow, since I did not use a riser. It is pretty much finished except for applying some form of string groove backing material. My hip went bone on bone, and for a while there, I was pretty much cut off from my outdoor activities, and never finished the project.
My mistakes were in underestimating the effort and tools required to smooth the silk down properly, and in leaving it too long. The string grooves were pretty much finished, and I cut two inches off each end, because it was not really usable in anything but flight type shooting at that length. If you plan on using one out of an elevated stand hunting, they need to be even shorter. In my case, I simply left it way too long. It is 72 plus after being cut down! It still isn't a practical woods bow.
It isn't even an impressive first bow, but I made it, and that suits me just fine.
If I do it again, I will start with an Osage board, and build pretty much the same bow again, a little shorter. Just because you are building a board bow, does not mean you can not build a nice bow, or that you can't use good bow wood in the process.