How to Measure a Curved Seam on a Paper Pattern

Eight Needles Journal · Measuring

A curved seam should be measured along the line that will actually be sewn. Measuring the nearby cutting edge answers a different question. Before choosing a tool, identify the stitching line and the start and end points in the pattern instructions.

Japanese sewing tools from the Eight Needles collection. Photo from the Eight Needles collection.

Work in manageable sections

Use a flexible ruler or move a tape carefully along the curve without pulling the paper. A measuring wheel offers a different way to follow the line. Whatever the method, keep the tool on the same reference line from beginning to end.

Account for what the pattern intends

Compare matching seams between their specified marks. Differences may be intentional, such as ease between notches. Do not redraw one piece simply because two totals differ; first check the pattern's construction notes and whether seam allowances were included in the comparison.

Check your method

Measure the same curve again from the other end. If the results differ noticeably, repeat more slowly and divide the curve into shorter sections. This is a measurement check, not a reason to force the pattern into a new shape.

A practical example

A sleeve seam appears longer than the armhole. Before altering either piece, compare the prescribed sections between matching notches and read the ease instructions. Measuring the entire outer cutting edge can hide both the intended distribution of ease and the location of the true stitching line.