Pat. The sinew I put down with Tb3 , have used it for 4 bows so far, will probably try hide glue sometime in future. Although I have not had a problem with the other. The sinew has allways went down really well. My other bows I had finished with paints and pigments and not had to have a real smooth back. Although the skins I didn't know. Seems to me that smoother would be better and filling the little valleys with either single strands of sinew or glue would be better than getting to aggressive with a file and sandpaper and reducing my sinew even further.