Why one sunscreen isn't enough
Every summer I hear the same question: "Which sunscreen should I use?" I always ask back — do you know your skin type and how sunscreens work? If you pick by SPF number alone, you'll either look ghostly white or break out.
Two mechanisms — reflection and absorption
Inorganic (physical) sunscreen uses mineral particles like zinc oxide (ZnO) and titanium dioxide (TiO₂) that sit on the skin's surface and reflect and scatter UV rays. It's low-irritation and recommended for sensitive skin and children. The downsides: white cast and a heavy finish.
Organic (chemical) sunscreen uses chemical filters that absorb UV and release it as heat. It blends in smoothly and leaves no white cast, but depending on the ingredients, it can sting the eyes or trigger sensitivity. It takes effect about 15 minutes after application.
Choosing by skin type
- Sensitive / acne-prone → Inorganic (especially ZnO-only formulas)
- Oily / breakout-prone → Low-irritation organic or hybrid
- Dry → Organic or hybrid with added moisturizers
- Children / pregnant women → Inorganic recommended
Enough product = real protection
The SPF50 rating in the lab is measured at 2mg per cm² (about 1g for the whole face). Most people apply less than one-third of that, getting less than half the listed protection. Remember: the size of two 500-won coins worth of product.
Action plan
Step 1. When to apply
- The last step of skincare (before makeup)
- 15 minutes before going out (especially for organic sunscreen)
- Reapply every 2–3 hours (use sticks or cushions)
Step 2. How to remove it
- Organic → Double cleanse with cleansing oil + mild-acid foam
- Inorganic → A single mild-acid foam wash is often enough
- Moisturize within 3 minutes of washing
Closing thoughts
Sunscreen is closer to a daily medication than a cosmetic. 1g a day, reapplied every 3 hours, applied properly. Do this over a lifetime, and your skin in your 40s will look like your 30s.