Safe fret crowning
Safe fret crowning was brought to guitar community in 2011 by inventor Davide Bissoli. It prevents the filing of the very top of the fret (where the strings touch). This made fret crowning become safe because this configuration doesn't allow to change the height of the fret. Fret crowning with the LittleBone Fret File (Bissoli Fret File) is done in a few steps where the very first step consists in filing away most of the material that must be removed from the sides homogeneously leaving the fret ready for a final rounding and refinishing with sand paper and other finer products.
How to use the Littlebone Fret file and the LittleBone ice