Have you ever wondered how close your shading system was to the shade guides?

We found that since teeth transmit substantially more light  than they reflect , it was best to study illumination and spectral light energy as it diffuses. As light travels it loses the longer wave lengths in the spectrum.  Rather than treat the ceramic as a canvas  to mask and reflect  specific shade  color, We approached shading  from the aspect of stained glass and use the illumination of the ceramic base to filter through and shade with illumination. Below is our QC files that we develop for each batch of shading frits. In random testing  we found if the shade match was 0.4 or less the shade match was considered terrific.

 In the shade match below we used a B1 to B2 shade tab match 

like wise we used a C12 to C2 match to check the "C" range shading of our frits.

To check the "D" range is different from A. B or C  ranges. D2 is actually a 0.5 "C" and D4 is a enhanced C2. D3 is an enhanced "A' range - (Makes you head hurt doesn't it.)  

All we did here was add to the existing base shade that which was missing to make a D3 appearance by filtering the illumination up through  the D range frit layer.

We used a C1 base shade and A chroma level of 1 (1% our frit shading palette enables 1 , 2 and 4 % chroma adjustments )

We had to make separate shades for 4M & 5M

 I am including a chart we worked out for matching 3D shades from classic shade blocks. It gives you a very good reference to obtaining a 3D shade from a classic block or base shade.

Check out your surface shading using this simple method - see if you can make a Classic "1" shade into a "2" shade in the same shade range -  and you can verify the spread with Photoshop.  

Jim Emmons CDT,FNBC / Spectrafire.com / [email protected]