How long is the best time to shine for nail art? Is it really better to have a long time?

The light does not need to be as long as possible, the key is to follow the product instructions and the power of the lamp to shine for enough time. Most gels have cured after enough time, and too long may cause the surface to turn yellow or brittle

General Recommended Time (Take 36W UV LED light as an example)                                        Base Adhesive Line:
Primer: 30-60S (thin coating)
Color glue: 45-60s per layer
Sealing: 60-90s (frosted seals take longer)
Special Adhesives:
Extension glue: 90-120s (need to be cured in stages)
Adhesive: 60-90s + 30 seconds to refill
For every 0.5mm increase in thickness, it takes 20% longer
It is recommended to use the principle of "thin coating with multiple layers" (0.3 mm per layer ≤)                         It's not that the longer you shine, the stronger it gets."
→ Over-curing reduces flexibility