Stitching holes that match your pricking irons

Why corners are the hard part

Walking a pricking iron along a straight edge is easy. The trouble starts at a corner. A side is rarely a whole number of stitches long, so the last press either runs past the corner or leaves a short gap before it. On a wallet or a card holder, that odd stitch sits right where the eye lands.

By hand, the usual fix is to start at each corner and spread the difference over the last few stitches. PatinaCAD does that sum for every side of every piece, before you touch the leather.

Prick a stitch line

1. Draw the stitch line. Most patterns use the Offset tool to draw it a set distance inside the edge, for example 3.5 mm.
2. Choose an iron in the Pricking irons list in the side panel, for example Diamond 3.85mm.
3. Press P for the Stitching tool and click the stitch line where the holes should start.
4. Move along the line. The holes show as you go, and the status bar gives their number and spacing.
5. Click to prick. To go all the way round a closed outline, click the start point again, or simply double-click the stitch line.

The run follows lines, arcs and curves joined end to end, so one run can go round a whole outline. Holes that are already there stay put: prick a tricky stretch by hand, then let PatinaCAD fill in the rest.

Fixed pitch, auto pitch or a set number of holes

The Spacing option decides how each side is spaced.

Mode	What it does	Good for
Fixed pitch (the default)	Every stitch at your iron's spacing. Before a corner, the odd length is shared over the last few stitches, none more than 10% off where the side allows.	Matching a hand iron exactly, and edges that are sewn together
Auto pitch	The spacing closest to your iron's that fits each side exactly, so there's a hole at both ends.	Even sides on a single piece
Number of holes	Exactly the number of holes you type.	Two edges that need the same count

On an open line, Fixed pitch stops at the last whole stitch before the point you click. It never squeezes in a short one. A 100 mm line pricked at 3.85 mm gets 26 holes and stops 3.75 mm short of the end. Auto pitch puts 27 holes on the same line, 3.846 mm apart, with a hole at both ends.

A hole on every corner

The Corners option decides which joints get a hole. The default, Hole on every corner, puts a hole exactly on every corner and spaces each side on its own. A joint counts as a corner when its angle is under 160° (you can change this), so a right angle is a corner and a gentle bend isn't. A small rounded corner, up to two stitches long, gets one hole in the middle of the curve. All junctions puts a hole at every joint between shapes, and Uniform runs the spacing straight through with no corner holes.

Here is a real example: a card holder whose stitch line is 89 × 57 mm, pricked with a 3.85 mm iron.

• Auto pitch: 76 holes. The long sides are spaced at 3.870 mm and the short sides at 3.800 mm.
• Fixed pitch: 76 holes. Every stitch is 3.85 mm except the last two before each corner: 4.075 mm on the long sides and 3.475 mm on the short ones.
• Uniform corners: 75 holes at 3.85 mm that ignore the corners, and one shorter stitch of 3.69 mm where the loop closes.

Pricking press by press

Manual mode works like the iron in your hand. Under the iron in the side panel, choose how many prongs to press with, for example 2, then click along the line. Each new press starts in the last hole, as it does at the bench. One prong fewer makes the next press one prong shorter, so the run ends exactly where you want. Press Esc to finish.

Tips

• Prick edges that are sewn together from the same corner, in the same direction, with Fixed pitch, and they match hole for hole. For curved panels, see gussets that line up.
• Before you cut, select the stitch lines and choose Stitch ▸ Count holes to check the count.
• Press F6 to see the holes as thread, front and back, with the stitch preview.
• Want the numbers without opening PatinaCAD? The stitch hole spacing calculator works out the count and spacing for one seam.

Good to know

• The pitch is the distance between hole centres, the same way irons are sold.
• Each hole takes the shape of the iron's blade: diamond, French, flat or round. To swap the iron on holes you've already pricked, select them and choose Stitch ▸ Change hole shape.
• Ctrl+Del removes the holes from the selected lines and keeps the lines, so you can prick again with other settings.
• The Stitching tool always opens in Auto mode. Manual mode lasts until you close PatinaCAD.