Here's a link to a tutorial I did on how to make a bone saddle for a guitar, mando, uke, banjo etc, etc. Bleached Bone saddle blanks for your guitar, bass, banjo, mandolin, bouzouki etc, etc.
10x Bone Guitar Saddle 2 7/8"x1/8"x3/8"(72x3x9mm) Unbleached Luthier
10x Bone Guitar Saddle 3"x1/8"x3/8" (76x3x9mm) Luthier Nut White
10x Bone Guitar Saddle 2 13/16"x1/8"x3/8" (72x3x9mm) Luthier nut
10x Bone Guitar Saddle 3 3/8"x1/8"x3/8" (85x3.5x10mm) Luthier Unbleached
10pcs Bone Guitar Saddle 2 13/16"x1/8"x3/8" (72x3x9mm) Luthier nut
10pcs Bone Guitar Saddle 3-3/8"x1/8"x3/8"(85x3.5x10mm) Unbleached Luthier