364 JOURNAL OF COSMETIC SCIENCE
RESULTS AND DISCUSSION
FILM THICKNESS
The thickness of the one-layer nail film on the plastic nail was in the range of 17–43 µm,
and the two-layer film in the range of 53–140 µm. On the silicone mat, the films were
slightly thicker, in the range of 32–55 µm for the one-layer, and 80–110 µm for the two-
layer films. The difference was not statistically significant between the one-layer and two-
layer films on plastic nails versus silicone mats. It can be seen in Table II that the thickness
of the two-layer films was approximately twice the thickness of the one-layer film with
both methods. These tests confirmed that the film used in this study for the tests, i.e., film
created on the silicone mat, was comparable to the film thickness consumers would create
in real life, i.e., thickness on the plastic nail, and allow for translatability of our results.
WATER LOSS VIA EVAPORATION
This test assumed that if the film is permeable for water, then water should be able to cross
the film via evaporation. The centrifuge tube was sealed well with the nail polish film to
avoid any other avenue of evaporation. The highest weight loss, after the control, at 25°C
occurred for Water Permeable 3 nail polish at both temperatures with both one- and two-
layer films (Table III). The order of weight loss was inconsistent for the other nail polishes.
Statistical analysis of the data showed that the control lost significantly more water than
any of the tubes covered with a nail polish film. Every nail polish film had the same percent
loss for the same thickness with no statistically significant difference between the films at
either temperature.
DYE LEAK TEST
Water did not pass through any of the nail polishes tested (Figure 1) for neither one nor
two layers of film. An observation was that the water-based food color droplet did not
stay spread out on the surface of Water Permeable 2 nail polish film after the 10-second
rubbing, which indicates a more hydrophobic surface compared to the other nail polishes.
Another observation made during the beaker test was a yellow tint that developed in the
beakers that were covered with Water Permeable 3 nail polish. This indicates that the film
Table II
Thickness Measurements
Nail polish Film on plastic nail (μm) Film on silicone mat (μm)
1 layer 2 layers 1 layer 2 layers
Traditional 1 27 ± 5 73 ± 24 42 ± 6 80 ± 6
Traditional 2 30 ± 8 67 ± 5 32 ± 6 97 ± 16
Water Permeable 1 17 ± 5 53 ± 12 32 ± 19 106 ± 12
Water Permeable 2 40 ± 14 140 ± 16 55 ± 6 110 ± 6
Water Permeable 3 43 ± 26 87 ± 12 32 ± 19 102 ± 0
Results are shown as average ± SD.

365 Water Permeability of Nail Polish
had a water-soluble component in it. The color additives are not listed individually on the
label (Table I), most likely they were part of the Til Permeability ComplexTM (Tuesday in
Love, Canada).
COFFEE FILTER TEST
Many consumers believe that if a nail polish is water permeable, water should pass through
the polish film and the coffee filter due to the paper’s ability to quickly absorb water and
allow water to easily pass through the filter. A blue dye was used to make it easier to
detect leaking of the water via the film into the beaker. A blue stain or at least a wet spot
was expected to show right under the nail polish film (see Figure 2A) if the dyed water or
simply just water was able to permeate through the film. In our study, blue color was not
detected under any of the filters, indicating that water did not pass through the nail polish
films (Figure 2B).
PAPER TOWEL TEST
Paper towel was chosen for this test because it is designed to absorb water through capillary
action. Therefore, many consumers conclude that if a nail polish is water permeable then
water should pass through the polish film and absorb into the paper towel. Paper towels are
made of cellulose fibers that attract water molecules and have a textured surface to increase
their surface area, which allows the paper towel to absorb more water. In this study, blue
Table III
Water Loss Test Results
Nail polish 1 layer 2 layers
Percent (%)
loss at 25°C
Percent (%)
loss at 45°C
Percent (%)
loss at 25°C
Percent (%)
loss at 45°C
Control 0.76 ± 0.07 3.58 ± 0.08 0.64 ± 0.00 3.65 ± 0.00
Traditional 1 0.14 ± 0.02 0.62 ± 0.16 0.10 ± 0.02 0.66 ± 0.01
Traditional 2 0.14 ± 0.07 0.60 ± 0.16 0.10 ± 0.01 0.85 ± 0.00
Water Permeable 1 0.16 ± 0.06 0.59 ± 0.00 0.11 ± 0.00 0.53 ± 0.01
Water Permeable 2 0.11 ± 0.02 0.56 ± 0.06 0.13 ± 0.01 0.67 ± 0.04
Water Permeable 3 0.22 ± 0.06 0.78 ± 0.01 0.14 ± 0.00 0.93 ± 0.14
Results are shown as average ± SD
Figure 1. Dye leak test of (A) one-layer film and (B) two-layer film after flipping the beaker upside-down and
then turning it back right side up, i.e., end of test.