They are perforated, to resemble the punched paper tape Tutte was so familiar with, and when viewed from one particular direction reveal an image of Tutte's head and shoulders.

BBC: Suffolk

Lamarr and Antheil proposed using a punched-paper roll like that of a player piano.

ECONOMIST: Player-piano pioneer

Before the introduction of magnetic tape, digital storage for early computers used punched cards, paper tape as well as more exotic technologies such as mercury delay lines and the phosphors on cathode ray tubes.

FORBES: Magnetic Tape Turns 60

At the same time, he switched from a paper strip to punched cards. (Making the cards the same size as dollar bills meant that existing storage cabinets could be used.) By clever wiring of the tabulating machine, it was possible to count the number of cards with particular combinations of attributes.

ECONOMIST: Millennium issue

His first design, patented in 1884, used a long strip of paper into which holes were punched to represent information.

ECONOMIST: Millennium issue

It gave rise to a new lexicon: swinging chad, hanging chad, tri-chad, pregnant chad and dimpled chad--a "chad" being the bit of paper that did not fully detach when the voter punched a selection.

FORBES: Hand Recount May Tip Election To Gore