In Thailand, cloth sizes are not standardized. T-shirts of the same size from different shops might not be exactly the same size, unlike GILDAN t-shirts that definitely standardize each size.

• Ultra Cotton is the US size. The width of each size is 5 cm. different or about 2 inches.
• Other t-shirts are the Asian size. The width of each size is 3 cm. different or about 1.2 inches.