20cm, 50cm or 60cm: Which Pattern Ruler?

Eight Needles Journal · Measuring

The right ruler length depends on the space around your pattern as much as the pattern itself. A compact ruler is easy to turn around small details; a longer one bridges more of a grainline or garment panel without being repositioned.

Bunka 20cm Pattern Ruler — A compact ruler is easy to turn around pockets and short edges.

Compare the three Bunka lengths

Ruler	Useful reach	Trade-off
20 cm · 1.2 mm thick	Pockets, cuffs, short seam allowances and small checks	Needs repositioning along longer pattern lines
50 cm · 1.2 mm thick	General pattern drafting and longer straight references	Needs more clear table space than a compact ruler
60 cm · 1.4 mm thick	Longer grainlines and larger pattern areas	The extra reach is useful only when the ruler can lie flat and be controlled

These transparent PVC models have metric markings, a 5 mm grid and a 12 mm seam-allowance guide. Their markings are protected inside a laminated construction. The 12 mm guide is a convenience, not a rule for every pattern: use the allowance specified for that edge. Half an inch is 12.7 mm, so 12 mm is not an exact imperial substitute.

Match the working area

Measure the clear space on your table before choosing a long ruler. If its end hangs unsupported, it becomes harder to keep flat. A shorter ruler can be more comfortable for cuffs, pockets and checking small distances between markings.

Avoid accumulated errors

When a line is longer than the ruler, make an overlapping reference rather than repeatedly marking from the previous endpoint. Check the completed line against the pattern instructions. Tiny alignment errors can add up when a measurement is built from many separate sections.

Use the grid to keep a line parallel

For a straight 1 cm allowance, align the ruler’s 1 cm reference with the seamline and draw along the appropriate edge. Keep the reference aligned along the full working section, rather than checking one end only. Use a sharp pencil so a thick line does not hide the difference between the seamline and the cutting line.

A straight ruler helps with straight sections. For a curve, make short perpendicular offset checks or use a suitable curve guide, then blend a smooth line. Do not force a rigid ruler to imitate a tight curve.

A two-ruler arrangement

For a compact dressmaking setup, keep a short ruler near the machine and a longer one at the pattern table. You do not need every length. Choose the second ruler only when it solves a repeated difficulty, such as a long centre line or an awkwardly small pocket corner.

Drafting is different from guiding a blade

These pattern rulers are for drawing and measuring. Use a ruler specifically designed for cutting when guiding a rotary cutter or craft knife; a blade can damage a thin drafting edge. Keep PVC rulers away from hot ironing surfaces and direct heat, and store them flat so they remain dependable references.

A practical example

A pocket piece and a full-length trouser panel do not need the same working reach. Use a compact ruler to check the pocket's short edges, then move to the longer ruler for the panel's reference line. Keep the smaller tool rather than replacing it simply because the project is larger.