This case study shows PZC measurements on Quartersawn and Flatsawn surfaces from a wood specie with evident flecks: European Beech.
Measurement surface is on top of each number
Here’s how the samples look like:
And the results…
The surface appearance is totally different between Quartersawn and Flat surfaces.
And yes, in this case chatoyance appears slightly higher (in terms of PZC) on quartersawn surfaces. Why?
Below are some pictures compared to the PZC distribution on the surface:
Interestingly, on quartersawn samples (such as Sample 1 above) flecks appears more chatoyant than surrounding fibers. Oppositely, on flatsawn surfaces (such as Sample 6 above) flecks appear less chatoyant than surrounding fibers.
Apparently, flecks contribute to overall chatoyance in the quartersawn surfaces.