When choosing sun protective clothing, the choice of fabric is really crucial and it directly determines the effectiveness of sun protection. Below are the key factors and recommended types of sun protection fabrics to judge whether they are good or bad:
Core criteria for judging whether the sun protection fabric is good or bad
1. UPF value:
The most important! UPF is an international standard that measures a fabric's ability to protect against UV rays.
UPF 15-24: good protection (blocks about 93.3%-95.8% of UV rays)
UPF 25-39: very good protection (blocks about 96%-97.4% of UV rays)
UPF 40-50+: excellent to very good protection (blocks more than 97.5%, up to 98%+ of UV rays)
When choosing and purchasing, make sure to recognize the UPF value indicated on the hangtag, and choose a product with UPF 40+ or 50+.
2. fiber material:
Polyester fiber: usually the best sunscreen effect. Its molecular structure itself can absorb ultraviolet rays very well, especially after UV treatment of polyester.
Nylon: also very effective in sun protection. Second only to polyester, it is equally effective at blocking UV rays.
Acrylic: also good for sun protection.
Natural fibers such as cotton, linen, and silk:
By themselves, sun protection is weak (unless woven very tightly and heavily).
However, many modern sun-protective clothing will use cotton blends (e.g. cotton + polyester) or special anti-UV treatments for cotton, which can also achieve high UPF values.
Untreated lightweight cotton and silk have poor sun protection.
3. Fabric density and structure:
Tight > loose: the tighter the fabric is woven or knitted, the smaller the gaps between the yarns, the more difficult it is for UV rays to penetrate. High-density Oxford cloth, canvas (even if cotton) sun protection is better than loose mesh cloth, lace.
Thickness: The thicker the fabric, the better it is at blocking UV rays (but breathability and comfort should also be considered). However, lightweight, high-density fabrics that have been specially treated can also provide good sun protection.
Structure: Multi-layer structure or special weave structure (such as some honeycomb structure) can enhance the sun protection effect.
4. color:
Dark color > light color: Dark color (e.g. black, dark blue, dark red) absorbs more ultraviolet rays, and the sun protection effect is usually better than light color (e.g. white, light yellow). The UPF value of the same piece of fabric will increase significantly after dyeing dark color.
5. Elasticity and Stretch:
Stretchy fabrics (e.g. spandex blends) will stretch when worn, resulting in larger pores in the fabric, which may lower its UPF value. When choosing, pay attention to whether the nominal UPF value is tested under stretching condition.
6. Special treatment process:
Anti-UV treatment: UV absorbers or reflectors (e.g. titanium dioxide, zinc oxide, etc.) are added during the spinning or finishing process. This is the key to the high UPF achieved by many lightweight sun protective garments.
Coating: A UV-shielding coating is applied to the surface of the fabric (but may affect breathability and feel, and may not be washable).
Which fabric is more sun-protective? (Comprehensive recommendation)
1. High-density polyester fabric with special anti-UV treatment:
Most recommended! The best overall performance.
Advantages: Good sun protection, lightweight, quick-drying, abrasion-resistant, not easy to wrinkle. The high density structure combined with the anti-UV treatment can easily reach UPF 50+. Ideal for making lightweight, breathable professional sun protection clothing.
Possible drawbacks: slightly less breathable compared to natural fibers (but good design will make up for it), static electricity problem (can be improved by blending).
2. Nylon fabrics with special anti-UV treatment:
Also very good.
Advantages: excellent sun protection, softer and more drapey than polyester, good abrasion resistance, quick drying.
Possible disadvantages: price may be slightly higher, sun protection may be slightly reduced when exposed to water (no need to worry about choosing a certified product).
3. High-density cotton or cotton blend fabrics (especially dark colors):
Suitable for those who prefer natural materials or need a certain thickness/stiffness.
Advantages: Good moisture absorption and breathability, comfortable to wear, natural and environmentally friendly. High-density, dark-colored cotton (e.g. denim, canvas) or UV-treated cotton blends (cotton + polyester) can also provide good sun protection (depending on the specific UPF value).
Disadvantages: Cotton is heavy, wrinkles easily and dries slowly when wet; untreated, lightweight cotton provides poor sun protection. To achieve high UPF, it usually needs to be thicker or specially treated.
4. Special sunscreen technology fabrics:
Some outdoor brands will develop patented sun protection fabrics, combining multiple fibers (e.g. polyester/nylon + spandex to increase elasticity), special weaving structures, advanced anti-UV coatings/adjuvants, to optimize breathability, coolness, elasticity, and other properties while ensuring a high UPF (e.g. Coolmax sun protection fabrics, sun protection fabrics with a “cool touch”, etc.).
Selection Key Summary and Recommendations
1. Recognize the UPF label is king! Don't just look at the name of the material or feel the thickness. You must buy sun-protective clothing that is clearly labeled with UPF 40+ or 50+. This is the most reliable standard.
2. Prefer polyester or nylon-based, high-density fabrics. They usually have the best balance of sun protection, light weight and functionality.
3. darker colors usually provide better sun protection. If sun protection is critical, give preference to darker colors.
4. Be aware of the stretching effect of elastic fabrics. If the garment fits well and is stretchy, make sure that the nominal UPF value is measured while the garment is being worn.
5. Consider comfort and functionality: while maintaining UPF, choose fabrics that are breathable, quick-drying, cool-feeling, or have a certain amount of stretch depending on your activity.
6. Be wary of “plain dark jackets”: A plain dark cotton jacket or sports jacket without a clear UPF rating may provide far less sun protection than professional sun protection and may be unstable (e.g., after washing, stretching).
7. Check the hangtag and product description: formal sunscreen clothing will be clearly marked UPF value, implementation standards (such as China's GB/T 18830-2009), fiber composition, washing and maintenance instructions.
8. Attention to care: wash according to instructions, avoid excessive use of fabric softener (may block the fiber pores to reduce the sunscreen), avoid prolonged exposure to the sun (although the sunscreen clothing sunscreen, but excessive exposure to the sun will accelerate the aging of the fabric).
In short, the best fabrics for sun protection are those that have been professionally treated for UV resistance, are dense, and are clearly labeled with a high UPF rating (40+ or 50+) in polyester or nylon. Be sure to make the UPF certification label the primary screening criteria when purchasing.
Our sunwear is made with fabrics with a UPF of 50+, if you are interested please contact us.
