At this point, the custard should be thick and shiny, but still pliable and easy to work with. It should have the texture of really soft butter. Transfer the custard to a 9 x 13 inch baking pan or glass casserole dish, spreading the custard out evenly across the pan. Cover with plastic wrap, pressing the plastic wrap directly on the custard to prevent a skin from forming. Chill until completely cool, preferably overnight. When the custard is ready to use, it should have the texture of margarine.