1 c Butter or margarine; -softened
1 c Shortening
2 1/2 c Sifted powdered sugar
6 Hard-cooked egg yolks;-mashed
2 ts Baking soda
2 ts Cream of tartar
1 tb Vanilla extract
5 c All-purpose flour
Paste food coloring=red/green/yellow
Cream butter and shortening; gradually add sugar, beating well at medium speed of an electric mixer. Add egg yolks, soda, cream of tartar, and vanilla, beating well. Gradually add flour, mixing well. Divide dough into 4 equal portions. Color one portion red, one yellow, one green, and leave remaining dough plain. Wrap each separately in plastic wrap, and chill at least 1 hour. Hand shape cookies into desired designs, or roll dough to 1/4-inch thickness on a lightly floured surface and cut with 2-1/2-inch cookie cutters. Place on ungreased cookie sheets. Bake at 350 degrees for 8 to 10 minutes. Let cool on cookie sheets 1 to 2 minutes; remove to wire racks and cool completely.