Here's what Morich told me about their matte finish on the Labyrinth. I had asked because the specs indicated it as 500 grit:

"The burgundy pad #7447 produces a 320-400 finish, but it isn't really a matte finish though, since it does leave lines in the ball. This surface is significantly stronger than the out of box surface. From there we use the green scotch brite pad #96, which produces a 400-600 finish and also leaves lines and is a little sronger than factory. To get closer to factory we simply use a worn out green pad at this point and it helps to smooth out the lines. The next pad we use is the grey pad #7448 which yields about an 800-1000 finish and is real close to matte, this finish increases the length of the Labyrinth significantly."

I know some balls are sanded to 600 grit and then use a liquid sandpaper type of product like Ebonite's old Quick Sand, which takes balls to 1200 grit, leaves them dull, but smooth. Now it's called Matte Finish, which I think meets your request for a definition.

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