Pricking irons, built in or your own

Why the iron belongs in the pattern

A pattern pricked at one spacing and stitched with an iron of another doesn't line up. Say your iron really spaces its prongs 3.9 mm apart and the pattern assumes 3.85 mm. Over a 200 mm seam, that small difference adds up to about 2.6 mm, two thirds of a stitch. When the pattern uses the iron you own, the holes you print or cut match the holes you punch.

The irons built in

Blade	Sizes
Diamond	3, 3.38, 3.85, 4, 4.5 and 5 mm, 1/8″ and 5/32″
French	3, 3.38, 3.85 and 4 mm, 1/8″ and 5/32″
Flat	3, 4 and 5 mm
Round	3, 4 and 5 mm

Each comes with a set of prong counts, for example 1, 2, 5 and 9 prongs for the 3.85 mm diamond iron. The inch irons keep their true spacing: 1/8″ is 3.175 mm and 5/32″ is 3.969 mm.

The four blade shapes:

• Diamond: a slanted diamond, the classic saddle-stitched look.
• French: a thin slanted slit.
• Flat: a straight slit.
• Round: a round hole, as from a round punch.

Add the irons you own

1. Open Stitch ▸ Pricking irons (Ctrl+H).
2. Select the iron closest to yours and click +. PatinaCAD copies it as a starting point.
3. Give it a name, choose the blade shape, and enter the pitch, the blade's width and length, and its angle. Round irons take a diameter instead.
4. Under Blades, list the prong counts you own, for example 1, 2, 6.
5. Check the preview of one press. Reverse blade shows the iron turned round.
6. Click Apply changes.

The pitch can be anything from 0.5 to 100 mm, so one list covers fine wallet irons and wide spacing for heavy straps.

Measure your iron

Measure across as many prongs as you can. Lay a steel rule along the prong tips of your longest iron, measure from the first prong to the last, and divide by the number of gaps. A 9-prong 3.85 mm iron measures 30.8 mm from the first prong to the last: 8 gaps of 3.85 mm. Better still, punch a row in scrap leather or card and measure the holes, since those are what the pattern has to match.

To compare with stitches per inch, divide 25.4 by the pitch: 3.85 mm is about 6.6 stitches per inch, and 3.38 mm about 7.5. The pricking iron size chart lists the common sizes side by side.

Pricking with your iron

Once you choose an iron, the Stitching tool uses its spacing and blade shape. In Auto mode it lays out stitching holes along a whole line, with a hole on every corner. In Manual mode it presses like the real thing: choose a prong count under the iron, click along the line, and each press starts in the last hole.

Tips

• Name your irons the way they're marked, with the maker and the size, so they're easy to find in the list.
• Use one iron for edges that are sewn together. A 3.85 mm panel and a 4 mm gusset drift a full millimetre apart within seven stitches. See gussets that line up.
• To try another iron on holes you've already pricked, select them and choose Stitch ▸ Change hole shape. The holes stay where they are and take the new blade shape.
• If the slants run the wrong way for the side you stitch from, select the holes and choose Stitch ▸ Reverse holes.

Good to know

• Your irons are kept in your browser on this computer. To take them to another computer or browser, use Export in the Pricking irons dialog to save them as a file, then Import it there.
• Pattern files keep each hole's shape, so a pattern looks the same on a computer that doesn't have your irons.
• Built-in irons can be edited but not deleted.
• A blade width of 0 turns each hole into a single line, for laser and cutting machines that should cut a slit.