Club orders tend to land in a rush before the season: new polos for the committee, trackies and jackets for players, caps for cricket, and a fresh set of sponsor logos because the sponsors changed over summer. Everything needs to match, and it all needs to be ready before round one.
Most of that gear is stretchy technical polyester. A crest digitised for a heavy cotton polo will pull a lightweight training top out of shape and pucker around the edges. We use lighter density and a stabilising underlay for stretch fabrics, and build separate files for caps and bags so the crest looks the same on every item.
Number construction is covered on appliqué numbers, and school sport uniforms on school uniform digitising.
Puckered crest on a training top? It is usually a file built for cotton, stitched on stretch polyester.