The object consists of two thick black pieces of cardboard (16 x 5.5 cm and 16 x 4 cm). One has been thickly wrapped with a black thread, while the other, narrower one has labels with instructions glued to both sides. On one side, these instructions read: "For a few words related to this text, see the other cardboard by spooling the thread from this piece of cardboard to the other."
The back side reads: "Before you begin to spool the thread onto this piece of cardboard in a smooth, even manner, write your last name and the date of the spooling here:
Having spooled the thread from one piece of cardboard to the other (which takes approximately 20 minutes), the participant of the action finds exactly the same text on the other piece of cardboard from which he spooled the thread. If the given version of "Spool" has been used previously, he will find the last name of the person who has already spooled the thread from the narrow piece of cardboard to the broader one. The difference in the width of the cardboard spools is intended to reduce to a minimum the participant's suspicion that he will find an analogous note on the other piece of cardboard.