.125 thickness is what I cut all of my inlay material. I use .0312 end mills and they are only just slightly longer than this. Other than Ivory, which is any size available, I try to use as wide as possible, up to 3 inches, and 10 inches in length. I glue all my inlay material to .125 hard board that I have sized to 3X12" in width and length. This way I can cut completely through the inlay material into the sacrificial board with no fear of damage to my table. I have some solvent that dissolves the glue, releasing the inlays. A 4X8' sheet of hard board is only around 5.00 and I have the H/D store cut it into 8 1X4' lengths and then just cut them into 3X12" widths on the table saw when I get home. I have a cabinet with dozens of different inlay materials all glued down and ready to go.