Sunscreen is the one product that genuinely changes how your skin looks in ten years. It is also the one almost everyone applies two or three times too thinly.
How much to apply
SPF50 protection is measured in a lab at a layer of 2 mg per square centimetre. For a face that is roughly a third of a teaspoon. Apply half as much and the protection does not halve — it drops considerably further.
- The two-finger rule: two lines of cream along the full length of your index and middle fingers is the dose for face and neck.
- A stick travels well but makes a thin layer easy to get: pass over the same spot three or four times.
- Do not forget ears, neck and the backs of your hands — they age first.
A day with sunscreen
Morning
The last step of the routine, 15–20 minutes before you leave. Makeup goes on top once it has sunk in.
After 2 hours outdoors
Reapply if you are in the sun, sweating or swimming. Indoors by a window it is not essential.
Afternoon
Over makeup, a stick or a sunscreen cushion is the easy way to top up.
Evening
Remove with cleansing oil, then a foam: sunscreen does not come off with water alone.
In winter and on cloudy days UVA does not go anywhere — it passes through clouds and window glass alike.
What the letters on the bottle mean
- SPF — protection from UVB, the rays that burn. SPF30 blocks about 97%, SPF50 about 98%.
- PA++++ — protection from UVA, the rays behind pigmentation and wrinkles. More plus signs is better.
- "Chemical" and "physical" describe how it works, not how safe it is. Korean sunscreens are usually hybrid, and lighter than European ones.
How to pick yours
- Oily skin — light watery sunscreen serums with a matte finish.
- Dry skin — creamy ones with hyaluronic acid or panthenol.
- Sensitive skin — mineral, fragrance-free, with centella in the formula.
- The main criterion is the one you do not mind applying generously, every day.
If sunscreen pills under makeup, the culprit is usually the layer underneath: give your moisturiser a minute or two to absorb and the pilling stops.
The most expensive routine without SPF works at half strength. The simplest routine with SPF is already a decent routine.