I thought it would be interesting to show the process of making blanks for bone rosettes, also called roses, or, in Arabic, shamsa.
I use white bone, sold as knife scales, in five pieces for a typical main rosette. This is my setup for jointing the edges of the scales. I use a granite surface plate as a flat sanding platen. 100 grit sandpaper is clamped under a fence board with a 90 degree edge, forming a shooting board.
I rub both edges of each piece until I have a perfectly flat edge. I sand only on the push stroke. This lessens the likelihood of sanding more material from the ends of the edge, creating a crowned shaped.
The edges are all jointed.
And come together with no gaps. Incidentally, I've stained this bone with chamomile tea in order to match the other roses of the vintage oud this rose is destined for.
The fifth piece is arranged along the ends of the other four. So I tape the four together for jointing their ends.
Jointing the ends of the four pieces. I tape them all together well after the edges mate perfectly.
The bone is glued with epoxy to a wood substrate. I use a dark wood like walnut so it will be less visible in the finished instrument. This is three alternating layers of .5mm walnut glued with epoxy. Yes, it's homemade hardwood plywood on a tiny scale.
I place some wax paper under the walnut to protect the granite and prevent adhesion. I apply a thin layer of epoxy to the walnut with a palette knife.
I make sure it covers the entire surface.
With the bone flipped upside down (the tape is on the other side) I run some glue over the joints, then I open up the cracks slightly and let the glue run in a little.
Then I place the bone onto the walnut substrate.
Followed by more wax paper...
And a layer of cork to distribute the pressure from the press.
I then place a square of particle board over the cork (and sometimes an extra later of plywood over that) and slide the whole works into the press, where it stays under pressure for at least 24 hours.
After I remove it from the press I apply the pattern with spray adhesive, drill holes in the voids and proceed with carefully cutting out the pattern.
This is a finished shamsa. Shamsa in Arabic means "sun".
Detail. Some of the lines in the center calligraphy (which is, incidentally, my name) are only a few thousandths wide. It's the walnut ply backing that makes this possible. Very fine jeweler's saw blades are also necessary.