Pressing is not ironing. Ironing moves the iron across the cloth to smooth it. Pressing sets the iron down, holds it, and lets heat and moisture make the fibre plastic so it takes the new shape as it cools. One is a smoothing action; the other is a shaping action.
The four tools
- The iron — heat, moisture and pressure in one tool. Steam is the part that matters most.
- The tailor's ham — a firm cushion with two curves for pressing darts and curved seams over a shape.
- The seam roll — a narrow cylinder for pressing a seam open without imprinting its allowances on the right side.
- The clapper — a hardwood block that traps steam in a seam and forces it through the cloth, setting it flat and sharp.
The sequence that produces flat seams
Press the seam flat as sewn
Before opening it, press the seam as it came off the machine. This sets the stitches into the cloth and stops them pulling.
Press the seam open, from the wrong side
Over a ham for a curve, on the board for a straight seam. Use the iron nose to open it, then the flat to press it.
Steam, then clap
For a crisp flat seam, steam it and immediately press the clapper down and hold for five to ten seconds while the steam escapes.
Let it cool flat
Do not move the piece while it is hot. The shape sets as it cools, and moving it early undoes the press.
Press as you sew, not at the end
Press every seam the moment it comes off the machine. A seam pressed while it is the only seam in the garment is easy; a garment unpicked and re-pressed at the end is a different job entirely.
Matching heat to fibre
| Fibre | Heat | Steam | Watch for |
|---|---|---|---|
| Cotton | High | Lots | Scorching if left in one place |
| Linen | High | Lots, while damp | Creasing as it cools if moved |
| Wool | Medium | Steam, with a cloth | Shine and scorch; use a pressing cloth |
| Silk | Low | Little, with a cloth | Water spots and shine |
| Synthetics | Low | Minimal | Melting; test on a scrap first |
An iron is a burn risk and a fire risk
Stand the iron upright whenever it is not in your hand. Never leave it face down on the board, and never leave it unattended with children or pets in the room. Let it cool fully before you empty or store it.
What the clapper does
A clapper is the tool that surprises people most. Steam a seam, then press a block of hardwood down on it and hold. The wood holds the heat in and gives the steam nowhere to go but through the cloth, which sets a seam sharper and flatter than an iron alone can manage. It is also the fastest way to sharpen a collar point.
The whole pressing kit costs very little next to a machine, and it changes the finish of everything you make more than any other purchase.
