I'm not sure how well it would work on the black. I haven't tried the black myself - mostly because I've heard the paper doesn't bond to the foam nearly as well on the black and comes loose very easily. I had initially hoped that the minwax treatment would help bond the paper to the foam better but I've found at least on the normal white board that's not the case, it doesn't weaken the bond but doesn't really help it any either.
On a related note - just have to say again I LOVE the minwax treatment. My second Versa had a horrible maiden (I was rushed building it, covered my CG marks and didn't realize the CG was about 2" further back than it should have been) and wound up in a canal. I thought for sure it was done for...but once it tried out it was fine. Heck the super sticky mud in the bottom of the canal didn't even stick to the mixwax and once the plane dried the mud just brushed right off! (Thankfully the water level in the canal was low enough my ESC/motor/RX didn't get dunked. My Lipo and lipo alarm got a nice swim though
On a related note - just have to say again I LOVE the minwax treatment. My second Versa had a horrible maiden (I was rushed building it, covered my CG marks and didn't realize the CG was about 2" further back than it should have been) and wound up in a canal. I thought for sure it was done for...but once it tried out it was fine. Heck the super sticky mud in the bottom of the canal didn't even stick to the mixwax and once the plane dried the mud just brushed right off! (Thankfully the water level in the canal was low enough my ESC/motor/RX didn't get dunked. My Lipo and lipo alarm got a nice swim though