Pantyhose sheerness is defined by what is called “denier”. Denier or den is a unit of measure for the linear mass density of fibers, i.e. thickness of material. The lower the denier number, the sheerer the garment. The higher the denier, the less sheer a piece of hosiery is, yet it is considered to be more durable. Usually ultra-sheer pantyhose are the ones 5 up to 15 denier and those are used primarily for special occasions and warm summer months. Actually, 3 is the lowest denier available, yet it is virtually impossible to find any pantyhose with denier lower than 5. 5, 7, 8 denier - ULTRA SHEER and TRASNAPRENT, usually made for the summer months and look like make-up for your legs. They are virtually invisible, mostly to cover up imperfections. If you select the color correctly, these pantyhose will virtually disappear on your legs.10 -15 denier - sheer pantyhose provide sheer coverage, perfect for special occasions and for warmer days. These are quite standard and wide spread. They are very transparent and give good coverage, yet could be almost invisible depending on the color. 20-30 denier - semi-sheer pantyhose, provide good coverage for your legs, more durable. 20 denier tights are very wide spread and are a must for fall and spring months. If you’re wearing skirts, dresses and suits, 20 denier tights would be aesthetically appropriate plus will keep you warm on the cooler days and nights! 20 denier tights could also be used under trousers and jeans to help shape the silhouette and keep you warm.40-50 denier - semi-opaque, excellent coverage, perfect for transitional months. Depending on the weave, 40 denier tights can have different appearance on the skin.