Schematic representation of how UV continuum (red) and Lyα photons (blue) propogate in the low-contrast regime. The medium illustrated here is composed of high-density clumps (containing H i + dust), distributed in an interclump medium of low density (HI+dust). In the low-contrast regime, the H i content in and between clumps are relatively high, which renders both regions optically thick for the Lyα photons. In this way, the Lyα photons can only escape the medium after undergoing multiple resonant scattering against H i atoms, increasing their probability being absorbed by the dust. The UV photons are not affected by the presence of H i atoms and propagate directly through the medium.