SKIN PROPERTIES OF TAIWANESE WOMEN 301 MEASUREMENT OF MOISTURE CONTENT The moisture content of the skin was determined using a corneometer CM 820 (Courage and Khazaka Electronic GmbH, Germany). A probe was pressed against the skin with a force of 1.5 N for 1 second. The measured area was 49 mm 2. Because the di- electric constants of water differ considerably from those of other substances, the mois- ture content of the skin could be determined by the change of capacity of the measuring capacitor. The results were recorded digitally in arbitrary units. RESULTS AND DISCUSSION LIPID CONTENT OF THE FACE The lipid content of the face is in the range of 4-254 }zgcm -2 for young Taiwanese women. Nogueira and Gabrielle defined skin type by different criteria for different parts of the face: a lipid content between 90 and 200 }zgcm -2 is defined as normal skin for the forehead, between 90 and 160 •gcm -2 for the cheek, and between 60 and 100 }zgcm -2 for the neck (5), because oil secretion is different in different parts of the face and neck. However, the same criteria should be used to determine skin type for different parts. An appearance of oily skin depends on lipid content only, not on loca- tion. Nogueira and Gabrielle also ignored the fact that weather is also a very important factor in oil secretion. Hot weather promotes more oil secretion, while cold weather suppresses it. To exclude the effect of weather, our measurements were taken at a temperature of 22-25øC and a relative humidity of 75%, and oil secretion was allowed to reach equi- librium before the measurements were taken. The same criteria were used to determine skin type for different parts of the face and neck. This criteria was determined by ob- serving the skin of young Taiwanese women in daytime in spring. Their skin surfaces were examined under an image through photofibers. If the lipid content was greater than 100 }zgcm -2, the skin was classified as oily. If the lipid content was smaller than 50 }zgcm -2, the skin was regarded as oil-depleted. A lipid content between 50 and 100 }zgcm -2 was taken as normal. The skin types of young Taiwanese women were then classified into six categories, listed in Table I. Twenty percent of the women had oily skin. Only ten percent had oil-depleted skin. Most women (70%) had combination skin Table I Skin Type of Young Taiwanese Women Skin type 1 2 a 3 b 4 • 5 a 6 Oily O/Normal Partially O/N O/oil-depleted Partially O/D Oil-depleted combination combination combination combination Percent (%) 20 16 23 6 25 10 aType 2: oily T-zone/normal combination. bType 3: partially oily/normal combination. CType 4: oily T-zone/oil-depleted combination. aType 5: partially oily/oil-depleted combination.

302 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Lipid Content of Each Skin Type (unit: •gcm -2) Skin type 1 2 3 4 5 6 Section 1 152 + 52 112 + 15 116 ___ 50 137 + 66 100 + 66 79 + 17 Section 2 119 + 25 66 ___ 19 74 + 29 39 --- 35 31 + 8 34 + 8 Section 3 122 + 33 63 --+ 15 75 --+ 24 27 + 20 34 + 15 42 + 18 Section 4 124 __+ 22 55 + 22 78 + 31 32 + 16 29 + 17 31 --+ 13 Section 5 108 __+ 18 63 + 26 69 --+ 23 20 --+ 10 25 --+ 15 27 --+ 9 Section 6 125 --+ 49 53 --+ 15 72 + 19 60 + 49 38 + 25 34 --- 9 Section 7 126 + 45 72 + 13 72 + 33 48 --+ 17 33 --+ 23 31 + 14 Section 8 136 + 47 80 +-- 14 84 +__ 37 47 + 23 28 + 21 48 + 22 Section 9 129 --- 39 62 + 16 77 +-- 33 51 --+ 42 27 + 20 47 --+ 12 Section 10 135 --+ 41 157 --+ 30 121 + 43 139 + 32 113 + 40 69 --+ 13 Section 11 157 + 69 150 --- 37 110 + 30 106 --+ 9 89 --+ 22 68 + 5 Section 12 147 + 51 128 __+ 43 95 --+ 29 121 + 8 70 + 26 62 + 20 Table III The Probability of Each Section to Become Oily for Partially Oily Combination Skin Type Forehead Nose Under nose/upper lip Chin Cheek Area around eyes Skin type 3 46% 73% 55% 36% 18% 18% Skin type 5 33% 67% 25% 17% 0% 0% type. Of those, 22% had oily T-zone/normal or oil-depleted combination skin, and 48% had a partially oily combination. Usually the T-zone, (i.e., forehead, nose, under nose/upper lip, and chin) has more oil se- cretion than the other parts of the face. The lipid content of twelve sections of the face is shown in Table II. Sections 1 (forehead), 10 (nose), 11 (undernose/upper lip), and 12 (chin) have a higher lipid content, except for skin type 1. For partially oily combination skin types (type 3 and 5 in Table II), the probability of each section to have oily skin is listed in Table III. The T-zone is still the most oily area, with the nose having the most tendency to be oily. Eighteen percent of skin type 3 had an oily cheek or oily area around the eyes, which is supposed to be a very dry area. MOISTURE CONTENT OF THE FACE The moisture content of facial skin of young Taiwanese women is between 23 and 147 a.u. The moisture content of each skin type is listed in Table IV. Different skin types showed similar values of moisture content, which implies that the moisture con- tent of skin is independent of its lipid content. Apparently, oil has no influence on dif- fusional water loss in the skin. Almost every Taiwanese woman has low moisture con- tent in the lower cheek (i.e., sections 8 and 9). Since the moisture content depends strongly upon the location on the face, but not on the amount of oil secreted, the skin type is mainly determined by the lipid content. Nogueira and Gabrielle defined hydrated skin as having a moisture content between 65 and 90 a.u., and very dehydrated skin as having a value below 65 a.u. (5). They ignored