Shortening a metal zip is a little tutorial for you to file away until you need it. Use it for shortening separating zips for jackets.
How did I learn to do this? One season, the designer I worked for used a lot of zips in her range. Zips were IN. She did zip fronted jackets, zipped pockets, zipped cuffs, etc etc. Everything had zips on, instead of the usual buttons or nothing.
I watched the zip rep (also known as “the YKK man”) shorten some separating zips we wanted that were the wrong length (he used my table). He was very quick at it, and kindly answered all my questions. Here’s how he shortened a zip:
Step 1: Measure the length you want, and place a mark on each side of the zip tape. How long should a zip be? Make it 1cm shorter than the edge to ensure it lies flat without the “wavy” look. For a long-line jacket, make it 1.5cm. The edges will be eased into the zip, but don’t worry; 1cm is a small amount and you’ll easily manage it. My zip is only about 7mm shorter than the front edge because it’s a short jacket with a short zip.
Step 2: Using a small pair of pincers (from a hardware or jewelry making shop), remove the top tabs and put them in a safe place.
Step 3: Still using the pincers, remove the metal teeth about 1″ above the marked position. You can see this causes some fraying of the tape, as the teeth are wrestled off. Don’t worry, you’ll deal with it in the next step.
Step 4: Use a flame to carefully melt the fuzziness on the zip tape. If the zip is a light colour, do this very conservatively or you’ll end up with black soot on the tape.
Step 5: Replace the top tabs. If you’ve lost one, the zip will still work with only one. Actually, the zip will still work with none, but I like to have them. Do up the zip to double-check it’s the right length. Cut off the excess tape. Zip shortened!