Trace the pattern when the sheet holds more than one size you may want later, when you plan to alter it, or when it is printed on tissue or in a magazine that you cannot replace; cut it when you printed it at home from a PDF and can print the pieces again, when you will only ever sew one size, or when it is a single-use project. For a PDF pattern the master is the file, not the paper, so cutting is the normal choice; for a made-to-measure pattern there are no other sizes on the page to protect. Tracing costs half an hour to an hour; it buys you the original, intact, for the next size, the next body and the next idea.
How do tracing and cutting compare?
| Feature | Trace | Cut |
|---|---|---|
| Time | 30 to 60 minutes extra for a dress | None |
| Other sizes kept | Yes, the sheet stays whole | No, unless you cut between the lines |
| Alterations | On the copy; the original stays clean | On the only copy |
| Materials | Tracing paper, pencil, ruler, weights | Paper scissors |
| Accuracy | A pencil line's width; curves can drift | Exact to the printed line |
| Durability | A sturdy tracing paper outlasts tissue | Tissue tears; printer paper lasts |
| Best for | Tissue patterns, magazine sheets, blocks, children's clothes | PDFs printed at home, one size, quick projects |
Why would you trace a pattern instead of cutting it?
Most commercial patterns print several sizes on one sheet as nested sizes: a set of outlines, one inside the other, usually five to eight of them. Cut along one line and the larger sizes are gone, since the cut passes through them; the smaller ones survive, but with a ragged edge. Tracing keeps the sheet whole, so a sister, a child who grows, or your own next size can use it later.
Tracing also makes alterations safe. If you lengthen a bodice, move a dart or blend from a size 40 bust to a size 44 hip, you do it on the tracing, and the original is there to go back to when the toile shows you went too far. Many sewists trace every pattern they alter for that reason alone.
Lastly, some paper is not worth cutting. The tissue in printed envelopes tears at a pin and crumples in storage; a magazine's pattern sheet holds a dozen garments printed over each other in different colors, and cannot be cut at all. A tracing on sturdier paper outlasts both.
When is cutting the pattern fine?
When the paper is replaceable or the other sizes are not needed. A PDF printed at home is the clearest case: the file is the master, printer paper is cheap, and the printing guide shows how to print it again at the right scale. Cut it, write the size and the date on each piece, and reprint if you alter it beyond repair.
A single-size pattern, a pattern for a child who will have outgrown it by the time you sew it again, or a quick project such as a scrunchie or a cushion cover, all cut without regret. The same goes for a pattern you bought in your size only, where the sheet carries no other.
A compromise for a nested sheet is to cut between the lines: trim the paper along the outside of your size, leaving the larger sizes' lines attached to the piece. You lose the smaller sizes but keep the larger ones intact for later, and the piece is ready in five minutes.
What paper should you trace onto?
- Tracing paper on a roll, sold for pattern-making or as sketching paper: thin, see-through, inexpensive, tears like tissue.
- Swedish tracing paper, a soft non-woven sheet: see-through, can be sewn as a toile, folds without creasing, costs more.
- Medical examination paper: wide, cheap, translucent enough to see the lines through, a little fragile.
- Dot-and-cross pattern paper: marked with a grid, opaque, so you trace over a window or with a tracing wheel rather than by seeing through.
- Baking parchment and freezer paper: narrow and available in any supermarket; fine for small pieces, a hassle for a skirt.
For blocks and patterns you will use many times, trace onto card or heavy kraft paper so the pieces can be drawn around with chalk on the fabric, as in a workroom.
How do you trace a pattern accurately?
- Press the sheet. A dry iron on low removes the creases that pull the lines out of place.
- Find your size and your pieces. Read the key: each size has its own line style. Highlight your size's outline in color before you trace; it stops the eye jumping to a neighbor where lines cross. How to read a sewing pattern explains the lines and symbols.
- Weigh the tracing paper down. Pattern weights or tins on the corners; no pins, which shift the layers.
- Trace the lines with a sharp pencil, a ruler for straight edges and a French curve or a steady hand for armholes and necklines. Keep the pencil on the inside edge of the printed line so the piece does not grow.
- Copy every marking: the grainline, notches, dart legs and points, dots, fold lines, button positions, the piece name, the number to cut and the size. A tracing without notches is a tracing you will regret at the sewing stage.
- Check the seam lengths. Walk the side seam of the front against the side seam of the back with the pieces on top of each other, as a check against a drifted curve.
- Label it with the pattern name, the size and the date, and note any alteration you make.
Tip: Trace the stitching line as well as the cutting line if the pattern marks both. Fitting and alterations happen on the stitching line.
Does the question change for PDF patterns?
Mostly it goes away. The master is the file: print, cut, and when you need another size print again. Many PDF patterns let you print only the sizes you want, with layers you switch on and off in the PDF viewer, which gives you a sheet with one clean outline and no tracing at all. Printing at home does cost paper and tape, and PDF vs paper patterns weighs that against the tissue envelope.
A made-to-measure pattern goes further: there is only one size on the page, yours. A Sewly pattern is drafted from your own measurements, so there are no neighboring lines to protect; if a measurement changes, you change the number, the pattern is redrawn, and you print the piece again. Tracing then only makes sense for a piece you have altered by hand on paper and want to keep.
If you sew the same pattern often, print it once onto heavy paper, or trace it onto card, so the pieces hold up to being pinned fifty times.
How do you store traced and cut patterns?
Fold each piece along the grainline rather than across it, which keeps the long straight edge accurate, and keep each pattern's pieces together: an A4 (US Letter) envelope with the pattern name and the sizes written on the outside, a zip bag with the line drawing in front, or a hanger with a clip for patterns you use often, hung flat so they never crease. Store tissue inside the tracing paper to protect it, and keep PDF files backed up with the version you printed noted on the paper.
Which should you choose?
- A printed nested pattern on tissue, in a size you may change or share: trace.
- A magazine or multi-garment sheet: trace; there is no other way.
- A pattern you will alter: trace, then alter the tracing and keep the original.
- A block or a favorite pattern you will sew again and again: trace onto card.
- A PDF printed at home: cut, and reprint when needed; trace only hand-altered pieces.
- A single-size pattern or a made-to-measure pattern: cut.
- A child's garment, a quick accessory or a single-use project: cut.
When in doubt, trace. The hour is cheap and the original is safe; few people regret keeping a pattern intact, and plenty regret cutting one.