Squaring Up and Cutting Straight Lines

Almost every project starts with a straight cut. A wobbly or wandering line at the cutting stage will show up in every step that follows — it throws off your stitch spacing, your edge finishing, and the overall look of the piece. Before you can cut a pattern out with confidence, it helps to practice squaring a corner and running a straightedge cut on scrap.

What you'll need

• A self-healing cutting mat, larger than the piece you're cutting
• A metal-edged straightedge or acrylic quilter's ruler (a plastic-only ruler will get chewed up fast)
• A rotary cutter for thinner leather (roughly 3-4 oz and under) or a head knife / utility knife for heavier weights
• A scrap piece of leather with at least one factory-straight edge, if available

Steps

1. Find or true up a reference edge. If your hide doesn't already have a clean factory edge, make one cut freehand along a chalk line first, then true it up against the straightedge on a second pass.
2. Square the corner. Lay the trued edge against one arm of a set square or the grid lines on your cutting mat, then mark a line at a true 90 degrees off it. This gives you two edges you can trust as reference lines for every later measurement.
3. Position the straightedge on the waste side of your line, not on the line itself, so the blade rides directly along the ruler's edge and the cut lands exactly where you marked it.
4. Anchor your off-hand flat on the ruler, fingers well clear of the blade path, and apply steady downward pressure so the ruler cannot creep mid-cut.
5. Cut in one continuous pull rather than several short strokes. With a rotary cutter, keep the blade tight against the ruler's edge and roll it away from your body; with a knife, keep the blade vertical rather than leaning it, or you'll undercut and taper the edge.
6. Check square with a set square after the cut, and true up any drift immediately rather than carrying an error into the next cut.