I understood that thread to say that the paint itself was approved, but only for use on approved materials - i.e. not on copper. Apologies if that was a misreading. Either way, it’s a bit of a moot point since as far as I can tell that paint isn’t sold anywhere anymore!
The LCC has reviewed your request and given our safety concerns we have decided that
Krylon Colormaxx Flat Black Paint + Primer is Banned for use in the VHS laser.
You should be able to find an alternate acrylic based spray paint that will work for your application.
Reasons for the ban are discussed below:
The Lowes site says that this paint is oil-based (i.e. not acrylic) and the MSDS states that this paint contains 19.02% Crystalline Silica, respirable powder by weight. This Crystalline Silica is known to be a human carcinogen.
The concern is that cutting and especially etching would release this Silica back into the laser cutter via smoke and also leave residue on the laser work piece.
A few comments from LCC
‘Crystalline silica is respirator territory’
Silica dust is REALLY nasty stuff and is one of the causes of miners lung.