Thermal evolution curves for a planet with a CMF of 0.35 and a mass of 0.2 M_J with varying atmospheric metallicities. The input internal temperatures are converted to ages, and the planet radius at each step is calculated by GASTLI. A higher assumed atmospheric metallicity leads to a lower total radius. After ∼ 1 Gyr, the change in radius due to the contraction of the planetary envelope is small even for low-metallicity atmospheres.