STA seems to be a water-based pen. Compared with the third generation, touch4 has no difference in writing, but it is still hard and the color is similar. WG and BG are better than the third generation, but there is no difference. Not as affordable as three generations.

I'm not used to water-based markers, but Xia Keliang's ultra-realistic water-based brushstrokes have a beautiful artistic conception.

Touch is an alcohol pen. Buy three generations.