How to Iron On a Patch

Spread a thick bath towel over a table and lay the jacket on top, front side up. Smooth the body flat with your hands, pull the sleeves straight and open the collar so nothing is bunched under the spot you plan to press.

Plug the iron in and turn it to its highest setting with the steam off. While it heats, set the patches, a Sharpie and a bed sheet next to the jacket so you are not hunting for them with a hot iron in one hand.

Set the patch on the jacket and move it around until it sits where you want it. Turn it, nudge it, step back and look at the whole jacket. Under London Lights starts with the sleeves and chest because those spots are trickier than the big open back.

Happy with it? Lift one edge at a time and put a tiny Sharpie dot at two or three points around the outline. The patch comes off for the next step, and the dots put it back in exactly the same place.

Slide the patch out of the way and run the hot iron over the marked area. Keep it moving for one to two minutes and hold the jacket flat with your free hand so the denim does not bunch under the soleplate.

This is the step most people skip. Warm denim lets the glue on the patch melt into the fabric from both sides instead of only from the top, which is the difference between a patch that stays and one that peels at the first wash.

Put the patch back down on the Sharpie dots, glue side against the denim. Check it is straight one more time. Once the glue melts there is no nudging it.

Lay a clean cotton bed sheet or pillowcase over the patch and smooth it flat with your hand. This is your pressing cloth. It keeps the iron off the embroidery so the threads do not scorch, melt or turn shiny, and it stops any glue that oozes out from ending up on your soleplate.

Set the iron down on the sheet over the patch and lean on it. Move it in slow circles the whole time, two to three minutes, working from the middle of the patch out to the edges. Do not park it in one spot, and do not lift it to check every ten seconds.

It feels like a long time. The patch packet probably says 30 seconds. Under London Lights found the short version left the edges lifting, so she presses until the whole patch has had heat and weight, edges included.

Lift a corner of the sheet and look at the patch. Run a fingertip around the whole edge and press down as you go. The denim will be hot, so go quick. A stuck edge feels like part of the jacket. A loose edge lifts against your nail.

Any edge that lifts, cover it again and give it another minute of heat with the iron pressing right on that spot. Then check again. When every edge holds, leave the patch to cool for a minute before you touch it more.

Every other patch gets the same routine: Sharpie dots, preheat, place, sheet, press, check. Under London Lights does the cuffs next. She lays the patch on the folded cuff, marks the spot with a Sharpie dot at each end, then irons it exactly as before.

Cuffs and sleeves are double thickness with seams close by, so slide a rolled towel inside the sleeve first. That gives the iron one flat layer to press on and stops the back of the sleeve from getting glued to the front.

Flip the jacket over and smooth the back flat. Lay out every patch you plan to put on the back so you can see the whole arrangement before anything gets ironed. The big one goes on first and everything else fits around it.

Hold the main patch with both hands and centre it between the side seams and below the yoke. Measure from each side seam to the patch edge if you are not sure. Then ask someone else to look. A back patch that is off by half an inch is the first thing everyone notices.

After the back patch has had its two to three minutes, fold the sheet away and run a finger around the entire edge. The big oval in the video needed a second round of heat on one side. That is normal for a large patch, because the iron cannot sit on all of it at once.

Cover the loose section, press for another minute, and check again. Once every patch on the jacket lies flat, let it cool completely. Add enamel pins last. They go through the fabric and cannot sit under the iron.