As a whole, the contact angle of water on the alginate-coated paperboards decreased more than that of the SPI coated
ones. This indicates that the water resistance of SPIcoated paperboards is higher than that of alginatecoated
paperboards. This result supports the findings of the WVP measurement which showed a lower WVP of the SPI-coated paperboards (Table 3). In addition, it is worthwhile to note that the degree of change in contact angle of water of each treatment is consistent with that of the WVP measurement.