Make a cornflour podge (aabout 2 tablespoons cornflour mixed with about an equal amount of cold water. Add to about a cup and a half of boiling water from the kettle. Use the resulting jelly to paint a thick layer onto the window pane. Cut out a rectangle of ironed lace using a template. Paste onto the pane, and cover with another layer of podge. Leave to dry. Wash with warm water to remove.