Sun protection is the foundation of all beauty treatments (including whitening, anti-aging, freckles, etc.). If you don’t use sun protection, it’s all in vain.
Sunscreen is an important (but not the only) sun protection measure. Its sun protection effect relies on the formation of a uniform and complete sunscreen film on the skin surface after applying sunscreen. The application method/technique may have a certain influence on whether such a sunscreen film can be formed. Influence.
1.Dotting? Push away? Or circle?
There are generally three ways to apply sunscreen: ① Dot application ② Always push in the same direction ③ Apply in circles. We use these three methods to apply the same amount of sunscreen in the designated area.
Figure 1 The process of applying sunscreen
Figure 2 Three ways to apply sunscreen
Figure 3 Microscope view of sunscreen distribution obtained by applying sunscreen in three ways
Spot coating: mottled, uneven, very uneven
Push it open and smear: there are lines and different shades
Apply in circles: Although there are lines, it is much more even.
Judging from the evenness of application, it is obviously better to apply in circles! So, what are the filtering effects of these three application methods on ultraviolet rays?
We enter the second step of the experiment: place a piece of white paper with UV fluorescence properties under the sunscreen film (simulating human skin) just applied. If ultraviolet rays can penetrate the sunscreen film, the white paper can be stimulated to emit blue-white fluorescence. The stronger the fluorescence seen by the naked eye, the more ultraviolet rays are transmitted through this place.
We can see that the one that reflects more blue-white fluorescence and has the worst sun protection effect is still applied by dots, followed by the one that is pushed in one direction.
When pushing the smear area (the square in the middle) in one direction, we can observe that the area smeared first is darker, indicating that the sunscreen film in this area is tighter, while the area smeared later becomes thinner and thinner.
In addition, when we apply this method, the direction is from left to right. From this, we can also observe that, in general, the initial area is thicker and the final area is thinner; there are also uneven textures locally.
Relatively speaking, the area applied in circles is darker and more uniform, indicating that the sunscreen effect is the best.
Why is this? Because when we advance from left to right, assuming that the amount on the right is larger, during the circle, we can bring it down, then to the left, and finally to the right. By repeating this cycle, a relatively even amount of sunscreen can be distributed to each part, thereby forming a uniform sunscreen film.
To sum up, applying sunscreen in a circular motion is better than applying it in parallel in one direction, and applying it in parallel in one direction is better than applying it in spots.
2.Four Key Points to Apply Sunscreen Correctly
The quantity should be sufficient:
Taking my face (an area of about 350cm2) as an example, the amount of sunscreen used must be more than 0.7g. At the same time, considering that some will stick to the palm of your hand, about 1g (about the size of the thumb cap) is more appropriate.
Apply evenly:
According to the above experiment, uneven application will also directly affect the effectiveness of sunscreen.
We can apply a little on various parts first, and then gently rub it in circles. Be careful not to use too much force, especially the lower eye sockets and other places where spots and wrinkles are prone to appear.
Do not rub immediately after applying:
In order to have a certain degree of waterproofness and strong adhesion on the skin, sunscreen will add a film-forming agent, and it takes a certain amount of time for the film-forming agent to dry and form a film.
Apply some loose powder as appropriate:
After use, you can apply some loose powder depending on the situation, which will further enhance its sun protection effect, and it can also resist sweat and oil at the same time to prevent the sun protection film from failing.
3.Three tips for reapplying sunscreen
Do commuters need to reapply: If you are a commuter and will only be exposed outdoors in the morning and evening, and do not wash your face, sweat, or exercise at noon, you do not need to reapply.
How to reapply during outdoor sports: If you are running or swimming outdoors, doing sports that involve sweating or contact with water, then you must remember to choose waterproof sunscreen, and reapply it every 80 minutes on average. And the amount of reapplying should be sufficient.
How to reapply after makeup: Applying sunscreen after makeup may affect the effect of makeup. At this time, it is recommended to spread some loose powder containing sunscreen, or use a spray (be careful to pinch your mouth and nose, close your eyes, and don’t let the particles be inhaled) in the lungs or in contact with mucous membranes). This way you can reapply sunscreen without damaging your makeup!
