Paper Cutting, Measuring and Marking
Cutting, measuring and marking decide whether everything later fits. The exam tests datum-edge discipline, allowance arithmetic, and safe, accurate guillotine work.
Measure from one datum
- Square one long edge first with a try square, then take every measurement from that same edge; never measure from a trimmed or damaged side.
- Mark on the waste side with a 2H pencil or an awl prick, never on the finished face.
- Use a steel rule for straight lines, dividers for repeats and a marking gauge for parallel lines on board.
- Keep tools true: a bent rule or worn square repeats its error on every piece.
Allowances to add
- Trim allowance 3 mm per side on a bound block; bleed 3 mm on printed covers; 10 mm glue tabs; 15 mm turn-in on case covers.
- Add board thickness at every fold when building a box or case.
Cutting practice
- Guillotine: square the stack against the back gauge, clamp firmly, check the setting on waste, then cut. A dull blade crushes, burns and leaves a ragged edge.
Worked example
Trim a 154 × 216 mm block to 148 × 210 mm. The difference is 6 mm in each direction, so 3 mm comes off each side. Cut the head first with the back gauge set at 213 mm (210 + 3), then the tail; turn the block and cut the fore-edge at 151 mm (148 + 3). Record the settings so all 200 copies come out identical.
Traps
- Measuring each time from a different edge, so small errors double.
- Forgetting that A6 is 105 × 148.5 mm before rounding; cutting 148.5 as 148 loses square.
- Cutting an unclamped stack, which gives a stepped, unsaleable edge.