A manufacturing method for a coating liquid, including: a preparing step of preparing aerogel particles, a water-soluble polymer having a hydrophobic group, and a liquid medium; and a mixing step of mixing the aerogel particles, the water-soluble polymer, and the liquid medium prepared in the preparing step and aggregating the aerogel particles to obtain a coating liquid containing aggregates of the aerogel particles, the water-soluble polymer, and the liquid medium.