Prepare some puff paste; roll out to about a third of an inch thick and cut into strips an inch wide and two inches long. Spread a baking dish thick with butter, arrange the pieces of paste on it, placing them upon their sides and leaving a small space between them. Put them in the oven and when they are firm and their sides have spread, glaze them with white of egg and dust with powdered sugar. As the feuillantines are cooked set them on paper and drain off any extra grease. Now mask them separately with small quantities of different colored jams. Arrange on fancy edged dish-paper or a folded napkin on a dish and serve.