PDF patterns are wonderful, instant, reprintable, and easy to store, but they only work if you print them at the correct scale and assemble the pages carefully. Get the setup right once and the rest is easy.

Print at 100 percent, always The single most important step is to disable any scaling in your print dialog. Look for an option labeled Actual size, 100 percent, or Custom Scale: 100 percent, and make sure Fit to page or Shrink to fit is turned off. Even a few percent of shrinkage will throw off the entire fit of a garment.

Check the test square Every good PDF pattern includes a test or calibration square, usually marked as a specific size like 1 inch or 5 cm. Print the first page, measure that square with a ruler, and confirm it matches. If it does not, your scaling is wrong. Do not cut a single piece until that square measures correctly.

Assemble the pages Most PDF patterns tile across many pages that you tape or glue together.

  • Trim the margin off the pages where indicated, often along a marked line on two sides.
  • Match the page numbers or the little triangles and registration marks printed at the edges.
  • Overlap each page onto the next so the lines flow continuously, then tape.
  • Work in rows, then join the rows, keeping everything flat.

Save your sanity Print on the lightest setting that is still readable to save ink, and consider a glue stick instead of tape for a less bulky join. Once assembled, you can cut your size, or trace it onto tracing paper so you keep the master intact for other sizes later. A careful print-and-assemble pass is the difference between a smooth project and a frustrating one before you have even threaded the machine.