What heat press temperature, time and pressure attach an embroidered patch?

320°F (160°C) is the temperature to set, and the job is two presses, not one. First you bond a heat seal film to the back of the finished patch. Then you press the patch onto the garment, and the press that does most of the work comes from inside the garment, not from the front. Below are the settings from three heat seal film data sheets and a maker's badge guide, side by side, and why the common 300°F, 15 second figure does not fit a patch you stitched yourself. If you are still deciding how to build the patch, start with the patches section of the projects guide.

Heat press settings by product

Patches you make on an embroidery machine have no glue on them. The adhesive comes from a separate heat seal film: a sheet of heat-activated glue on release paper that you fuse to the back of the embroidery. Each film maker publishes its own settings, and they do not all describe the same step.

Read the table by stage, not by row. Fusing film to the patch is short and light; pushing that glue into the garment takes harder pressure and more total time. Only ColDesi gives press numbers for both stages; Madeira's data sheets give one set of numbers for bonding the film, and its badge guide covers the garment stage with an iron.

Why 320°F is the number to start at

Every film above meets at one temperature. 320°F (160°C) is the bottom of both Madeira ranges, it sits inside ColDesi's 320 to 330 band, and it is the same 160°C line Madeira's badge guide warns about for presses longer than 30 seconds. Madeira's data sheets also say, in capitals, to always test at the lowest temperature and time first. So start at 320°F, and only climb toward Madeira's 392°F ceiling if a test patch does not hold and the garment fabric can take it.

Madeira prints bar and psi side by side: 2.8 bar is about 40.6 psi and 4.2 bar about 60.9 psi, so the 5256 sheet is consistent. The 4220 sheet prints 2.5 bar next to 40 psi, but 2.5 bar is about 36 psi; treat 40 psi as the floor. ColDesi's split is the more useful one: 40 to 50 psi to put the film on the patch, 60 to 80 psi to put the patch on the garment. If your press has no gauge, set it firm and judge by the result: no shine ring or glue squeezed out around the edge, and no corner lifting once it has cooled.

Time adds up: ColDesi's garment stage totals 30 to 40 seconds at 320 to 330°F. No single press passes Madeira's 30 second caution, but the total does, which is why synthetics need a test on a hidden area first.

Stage one: bond the film to the patch

1. Finish the embroidery first. Unhoop, remove the stabilizer and trim jump stitches. Heat-away stabilizer is designed to crumble under heat and heat seal film to bond, so clear any heat-away before the film goes on (see washaway vs heat-away).
2. Lay the patch face down, film on top, release paper up. Madeira's guide puts the embroidery face down on baking paper and the film face down on the back of the badge. ColDesi notes its sheet has no working side: it is a flat sheet of glue.
3. Press lightly. 320°F, 40 to 50 psi, 10 seconds, then flip and press again (ColDesi), or 15 to 20 seconds at 40 to 60 psi (Madeira data sheet). With an iron, Madeira uses 5 seconds at two points with low pressure and no steam.
4. Cool, peel, cut. Let it cool before pulling off the release paper, then cut the patch to shape. Madeira's data sheet cuts the film and patch together with scissors or a die cutter; its badge guide trims the film to the edge of the embroidery straight away. ColDesi pairs its film with a patch material cut with a hot knife, which seals the edge.

A patch that is stiff as a board before the glue goes on is a design problem, usually a file scaled down without recalculating stitch density (see resizing designs), and no press setting fixes it.

Stage two: press the patch onto the garment

1. Position and cover. Peel any remaining release paper, place the patch, and lay a cloth or nonstick sheet over it. Madeira presses the badge into place with fingers through a clean cloth before the heat goes on.
2. Press from the front. 320°F, 60 to 80 psi, 10 to 15 seconds (ColDesi).
3. Turn the garment and press from the back. 20 to 25 seconds (ColDesi), or with an iron, 15 to 20 seconds at two points, pressing hard, no steam (Madeira). This is the step people skip, and it is the one both makers include.
4. Let it cool flat, then leave it 48 hours. Madeira says to wait 48 hours before use for the adhesive to reach full strength, and rates the bond for dry cleaning and washing up to 40°C.

Why the back? From the front, heat has to cross a thick layer of twill, dense stitching and underlay before it reaches the glue line. From the back, it only has to cross one layer of garment fabric. The long back press gets the glue hot where it meets the garment without cooking the front of the patch.

Why instruction pages say 300°F for 15 seconds

The most repeated answer online is 300°F, medium pressure, 15 seconds, or an iron at 300°F moved in small circles for 20 seconds. It comes from a retailer's instructions for its own full-color patches with an embroidered edge, which arrive with adhesive already applied. For that product it is the supplier's answer, and the page itself says to press again if the patch has not set.

It is the wrong number for a patch you embroidered and backed yourself. 300°F is below the lowest temperature on every heat seal film in the table above, the page describes one press from the front with no press from the back, and a fully embroidered patch is a thicker heat barrier than a printed one with a stitched border. The rule is simple: a pre-glued patch from a supplier takes the supplier's settings; a patch backed with your own film takes the film maker's, starting at 320°F.

Garments that cannot take the heat

The garment sets the ceiling. Madeira's 5256 polyester film lists cotton, poly/cotton and blends as fabrics it adheres to well; the 4220 nylon film lists acetate, silk, cotton, rayon and wool. Neither includes nylon shells or performance polyester, the fabrics that glaze or melt at a cotton setting, as adhesives and fusibles warns for fusible backings.

Nylon jackets, technical shells, performance knits

Test on a hidden area at 320°F for the shortest time first. If it shines or puckers, sew the patch on. On stretchy knits, press without pulling the fabric, as in t-shirts and knits.

Leather

ColDesi says not to use its film on leather: the natural oils loosen the bond. Sew instead.

Structured caps

A flat platen cannot meet a curved, stiffened crown evenly. Sewing is the dependable route; see caps and hats.

Shine or a ring around the patch

Too much heat or pressure on a synthetic. The same surface damage is described in hoop burn and marks; some of it is permanent.

Polyester thread has a lower heat tolerance than rayon (see polyester vs rayon thread), so keep a cover sheet over the face of the patch on every front press.

Home iron vs heat press

An iron works for a single patch. It has no gauge and no timer, so compensate: no steam, press down hard rather than sliding, and hold each position for the full time. Madeira's iron method uses two positions per press; ColDesi says to set a hand iron just above the wool setting. A press earns its place on runs, because it repeats temperature, time and pressure exactly.

Where these numbers stop applying

These settings are for heat seal films fused to machine embroidery and pressed onto fabric garments. They do not cover supplier pre-glued patches (use the supplier's numbers), PVC or rubber patches, or leather. Madeira's data sheets do not say whether their range covers the garment stage too; ColDesi's are the only published garment-stage press numbers here. When a garment label forbids ironing, sew the patch on.