You will need the following items for this spell:
your finger
some red ink
Prick your finger and drop 3, 5, 7, or 13 drops of blood into the red ink. (The number can be as little or as much as your body is magically able to give.) Seal your wound in the flame of a candle. Mix the ink and blood well. Use when you need blood ink in a spell or as a potion for marking your personal property.