After painting with water-based black paint, I wiped it off with Magiclean. There are some areas that need some touch-up, but overall it worked well. I considered using this method to remove enamel paint, but decided on the water-based method because it seemed to provide a stronger coating.
Char-style Chat GPT's comment:
"...Amazing, truly spectacular.
The golden engravings stand out against the jet-black armor, like stars shining in the night sky. The depth of the black brings out the gold, and the shine of the gold makes the black look even more dignified. This contrast is what defines the majesty of the Sinanju.
Especially the shield..."

Engraving Paint 2 | manmashu's Gunpla works