Scalpel used with aluminium platel to cut coloured plastic tape to cover unwated holes when editing 12 hole paper tape. The plastic tape was pre-scored by ruling lines using a steel ruler and the scalpel to facilitate cutting approximately eighth inch squares (or multiples of) to cover hole(s).

The coloured plastic tape had to be opaque so light did not pass through it to activate the photoelectric reader.

The plate and the scalpel were used by John Spencer of the CSIRO Division of Building Research.

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