What does a high percent transmittance mean?

The formula for percent transmission is percent transmission = i/i₀ X 100%. “i” stands for the intensity of light leaving the sample, and i₀ stands for the intensity of light entering the sample. If the sample does not absorb light, i is equivalent to i₀, and thus the percent transmittance = 100%. Thus, a high percent transmittance indicates that little to no light is being absorbed. The opposite is true if the sample has a low percent transmittance. A low percent transmittance indicates the greater amount of light absorbed; if a sample absorbs light fully, i = 0, and percent transmittance = 0.