Heat using a bain-marie until Gesso becomes warm and fluid.
Apply successive coats with a brush until the required level is reached. Each coat can be applied as soon as the previous one is cold. After a few hours Gesso will set hard and can then be smoothed carefully with a very fine abrasive. When using Gesso with metal leaf wet the Gesso to revive the adhesive properties prior to laying the metal leaf.Gesso