You're watching two batches of what should be identical clear resin formulations. Both contain pearlescent mica powder at the same loading. One stays suspended for hours. The other shows a dense pearl layer at the bottom in twenty minutes. Same pigment supplier, same D50 spec sheet, same mixing prot...
You've specified a chameleon paint system for an automotive topcoat, selected your color shift mica powder, and now the applicator is reporting uneven color travel or worse—outright particle dropout in the gun. The particle size wasn't wrong on the datasheet. It was wrong for this system.
Sel...