@Nadia Bouhdili just reminded me that I meant to post about this here. Vaishali told us about Kuretake in class, and I found this set had some excellent gold watercolors (6 shades of gold!) at a very reasonable price at Amazon US. Great way to practice gold work before springing for shell gold: https://www.amazon.com/dp/B01H75AFHS/ref=cm_sw_em_r_mt_dp_U_-M0hFbR8VESJA
Heres how the gold looks on burnished paper:
Nadia, are these bound with fish glue or gum Arabic, do you think? I ask, because I have a tall, skinny bottle of Kuretake gold paint that seems shinier and more water resistant when dry than the Finetec/Colirio due in part, I suspect, to possibly being bound with fish glue rather than gum.