True goldenrod paper is made from a dye which is an acid-base indicator. This paper turns bright red in bases such as ammonia, baking soda or washing soda and returns to bright yellow in acids such as vinegar or lemon juice. Make your own indicator paper or use to preserve fingerprints. Instructions included. Color-changing goldenrod paper has become very difficult to find. Ours is guaranteed to be color-changing. Standard US Letter size, 8.5 X 11 inches.