Two factories can quote the same woven label 20 to 30 percent apart, and the reason is usually not the yarn but the cutting. Labels are slit from a continuous woven tape, and how the cut edge is sealed and how clean it is decides whether the label frays after washing, scratches skin or can be made in a shaped outline. Understanding this before you negotiate price is worth more than pushing the unit rate.

This guide covers four things: how hot cutting, ultrasonic, laser and cold cutting actually differ; which products need an upgraded method; how the cut edge should work with folding and sewing; and how to inspect the edge on arrival.

1. Four Cutting Methods That Also Seal the Edge

Polyester is thermoplastic: heat melts the cut edge and locks warp and weft together, which is why hot cutting and ultrasonic sealing prevent fraying. Cotton labels have no melting point, so the edge has to be solved by folding, binding or weaving it in. Choosing a cutting method therefore starts with the yarn you are using.

Method How it cuts Best for Watch out
Hot cut A heated blade presses through and seals; fast and cheap Standard flat labels, large runs, straight edges A melt bead forms and pale shades can show a yellow edge; too hot a blade hardens the border
Ultrasonic High-frequency vibration melts and cuts while pressing a soft edge Fine small text, thin labels, skin-contact placements Needs an ultrasonic die, costly on shaped outlines; slower than hot cutting
Laser A beam vaporises the material, no tooling, high precision Shaped outlines, cut-outs, very small sampling runs Slight scorch and smell at the edge, trial pale shades first; slow in bulk
Cold cut Mechanical shearing, no sealing, the flattest edge Cotton or blends, a raw-edge hand, when folding or binding follows

2. When You Must Move to a Better Method

  • Text under 2 mm or very fine lines: a hot-cut bead smears small lettering and the last character breaks up; ultrasonic holds it
  • Shaped outlines (curves, cut-outs, logo edges): laser ten pieces first to confirm shape and hand, then decide die or ultrasonic tooling for bulk
  • Edge against skin (neck labels, childrenswear): edge softness affects returns more than looks; ultrasonic pressing usually beats a hot-cut hard border
  • Cotton or non-melting fibres such as FR yarns: heat cannot seal them; use cold cut plus folding or binding, or switch to a woven-edge construction
  • No fraying after washing: whichever method you choose, pull samples and run five 40 °C washes — a dry sample tells you nothing

3. Cut Width Has to Follow the Fold Style

The three common folds make very different demands on the cut edge: center fold needs symmetry on both sides, end fold needs 8–10 mm of turn-back at each end, and loop fold leaves a seam allowance at one end. Cut too narrow and it will not fold; cut too wide and it wrinkles after washing — both look fine on a sample and then appear in bulk.

  • Keep the fold line off the melt bead: the bead is stiff and folding on it whitens and cracks; move the fold 1 mm inward
  • Keep the seam 1.5–2 mm from the cut: too close and the needle breaks the sealed yarns; the edge opens after two washes
  • Same cut direction across the lot: warp-cut and weft-cut edges feel different; mixing them gives soft and stiff labels in one batch

4. Where the Cost Difference Comes From

Hot cutting is cheap because a blade goes straight through; ultrasonic costs live in the die and the slower pass; laser costs live in machine time. Shaped or cut-out labels need a die or ultrasonic tool, a one-off charge that should not reappear on repeat orders — get that stated on the first quotation.

  • Laser is fastest for sampling — a shape in one or two days — but the hand differs from bulk; approve the shape first, then cut tooling
  • An ultrasonic die typically adds 3–5 days to standard lead time and more in peak season; build that into the schedule
  • For small shaped runs a steel die is cheaper than an ultrasonic tool, but it does not seal the edge — folding or binding is required, and that labour belongs in the comparison
  • Four lines belong on the quotation: whether cutting is included, whether tooling is included, who owns the tool, and whether a change of method is re-priced

5. Incoming Inspection: Three Looks, One Pull, One Wash

  1. Look at width: consistent across the lot, no burrs, no visible scorching — check pale shades first
  2. Look at the bead: too thick means the blade ran hot and the edge will be stiff — reject it for skin-contact styles
  3. Look at direction: is the fold line square to the cut, and consistent within the carton
  4. Pull one: a gentle crosswise pull should not draw yarns out — three pieces settle it
  5. Wash one: five pieces through five 40 °C machine washes and check fraying, curling and whitening — this exposes cutting problems best
💡 Tip: for shaped or fine-text labels, have the factory laser ten real pieces first to confirm outline and hand, then decide between ultrasonic and steel tooling. Two days here saves a tooling redo.

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Planning shaped, cut-out or fine-text woven labels? Send the artwork, finished dimensions and expected volume; we will propose a cutting and sealing route that matches your fold and cut laser samples first so you can approve the shape. Sampling 3–7 days, bulk 10–25 days.

Ask about label cutting →