Sift together flour, cream of tartar, baking soda, and salt; set aside.
Cream butter and sugar until light and fluffy. Add vanilla and eggs; mix well. Stir in dry ingredients; mix well. Stir in walnuts.
Using lightly floured hands, form dough into a long roll. Refrigerate overnight.
When ready to bake, preheat oven to 350 degrees. Lightly grease cookie sheets or line with parchment paper. Slice 1/4 inch thick; bake 10 to 12 minutes.
Recipe submitted by Joyce on 10/8/00