A clean circle cut from vegetable-tanned leather beside wing dividers and a scratch awl on a workbench.
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Cutting a Clean Circle in Leather

ByPeter Joeseph 'Briefcase Maker' Kalafatis

A straight line forgives a wobble. A circle shows every one of them.

A circle is the least forgiving shape you can cut in leather, because the eye knows exactly what a circle should look like and catches a flat spot from across the room. A rectangle with a slightly bowed side still reads as a rectangle. A coaster with one lazy stretch of edge reads as a mistake. The job breaks into five steps, in the order they happen on the bench: pick the tool by the size, find the centre and mark the line, cut, and clean the edge. The fifth is admitting where your hands can’t do it alone.

Video: OLFA Rotary Circle Cutter, from OLFA North America Inc on YouTube.

Pick the tool by the size of the circle

Small holes get punched, middle circles get a cutter, big or heavy ones get a knife.

Hands cutting a circle in leather with an upright knife while turning the leather on a cutting mat.

Under half an inch, don’t cut at all. Punch. Weaver Leather Supply’s round drive punch comes in sizes from 2 mm to 10 mm plus 13 mm, in hardened steel, and Weaver says to drive it with a mallet or maul, for controlled, repeatable results. Its Master Tool round punch runs up to 7/16 of an inch and, being a one-piece belt punch with no throat, reaches anywhere on the piece. One reviewer on that page found heavy leather opens the hole wider than the size stamped on the tool and suggested going one size down. Test on scrap from the same hide before you commit.

For the middle range, a rotary circle cutter does the work. OLFA’s CMP-3 Rotary Circle Cutter adjusts from 1-1/2 to 8-3/4 inches and runs an 18 mm rotary blade, and OLFA’s own page on it lists leather among the materials it cuts. The older OLFA CMP-1, a compass with a small knife blade, cuts circles up to 6 inches, though its listing names paper, film, card and light wood, not leather.

Weight decides the rest. On Leatherworker.net, in a thread asking what are ways to cut a circle, one member said he reaches for an OLFA circle cutter only “if the leather isn’t over 8ish ounces.” Past that, the same thread turns to knives and templates, and another member said flatly that he doesn’t recommend rotary cutting for rounds. For repeats, Tandy Leather’s cutting guide points to a die and a clicker press, which is a factory answer to a factory problem. One circle doesn’t need one.

My opinion: a beginner with one coaster to make should buy nothing. A sharp knife, a template and patience will do it, and the cutter only starts earning its price somewhere around the second dozen. I’d also say the weight question matters more than the tool question. The leather I work most is thick bridle, and nothing about a wheel on a ratchet handle makes me think it was built for that. I’d take a knife to a heavy circle every time and keep the wheel for the light stuff it was designed around.

Find the centre and mark the line

Every tool that swings a circle wants a hole in the middle of it.

That’s the first problem, and the forums have been solving it for years. Dividers and compasses need a pivot, and the pivot leaves a prick in the grain that won’t come out. In a long thread on ways to make circles and arcs, one member’s fix was to lay a scrap of leather over the centre point and anchor the dividers there instead. The same trick works under a rotary cutter: the member in the 2014 thread pins a scrap under the centre point when the piece can’t take a hole.

If the centre is going to be punched out anyway, as on a washer or a ring, the problem disappears. Put the pivot where the punch will go.

Mark with something that cuts a fine line. Rocky Mountain Leather Supply’s beginner picks list an economy adjustable compass at $9.99 and a large wing divider at $59.99, and a scratch awl from $3.99. Without either, the old answers still work. The same arcs thread lists a saucer, a coin, a can, a CD and a plastic drafting template with circles in graded sizes. One member there said the craftsman who taught her would set a saucer on wet leather and trace it with a stylus.

Scribe the line on the grain side, light and continuous. Then look at it from arm’s length before a blade goes near it. A bad mark is free to redo. A bad cut is a new piece of leather.

Cutting with a knife

Light passes, the blade straight up, and the leather turns instead of the wrist.

Macro of a leather circle's edge, half raw from cutting and half bevelled and burnished.

Start sharp. MAKESUPPLY’s tips for cutting curves open with replacing or polishing the blade, and CÍ Official’s guide to why tight curves go wrong blames a dull edge first, before the hand. A dull blade drags through a curve and tears fibre. On a circle that drag shows up as a ragged arc you’ll be sanding out later.

Keep the blade vertical. MAKESUPPLY warns that a leaning blade undercuts or overcuts, and CÍ adds that a tilted blade bends the cut wall even when the top line looks right. On a circle that matters twice, because a lean that changes as you go round leaves a wall that’s square in one place and slanted in another. You’ll feel it later in the burnish.

Don’t try to finish in one stroke. Both guides say to set a shallow first pass and deepen it, and MAKESUPPLY says to cut with the shoulder rather than the wrist. Tandy says the same about turning: rotate the leather under the blade instead of twisting the hand. Tandy also says “A round knife or head knife gives you better control on arcs,” and I’d agree for thick leather, though a snap-off blade does fine on lighter weights.

Two forum tricks are worth a try on scrap. One: clamp a rigid template, metal or hardboard, over the leather and run a razor knife around it in one direction only, the method a member in the 2014 thread recommended when no punch is big enough. Two, from a 2010 thread on cutting a circle: drive a nail through the centre into the bench, pin a blade at the radius, and turn the leather around the nail. It leaves a centre hole, so save it for pieces that get one.

Go slow at the end. The last inch of a circle meets the first inch, and that’s where a step shows. It’s the same discipline as punching stitching holes around a curve, which I do one step at a time. My opinion: a curve gives back every hurry you put into it.

Cutting with a rotary circle cutter

Set the radius, set the pivot, and let the tool keep the shape.

OLFA’s leather tray project walks through the CMP-3 on leather salvaged from an old couch. Flatten the leather on a cutting mat. Practise on scrap first. Uncap the compass point, set it at the centre, push the blade guard up and ease the blade into the leather. Then hold the ratchet handle in the dominant hand and move clockwise at a steady pace with steady pressure, while the other hand feeds the leather round so the cut never stops. OLFA’s product page says the ratchet handle is there to save the wrist on circular cuts.

That’s upholstery leather, thin and soft. On veg-tan, the forum advice about weight applies. Another member in the 2014 thread said he likes a rotary-type cutter because it seems to need less downward pressure. On heavier leather, plan on several passes rather than one hard push. A wheel forced through thick leather wanders, and a wandering wheel cuts a spiral, not a circle.

Two habits keep the rotary cutter honest. Don’t lift and restart mid-circle if you can help it, because the restart is where the step forms. I’d rather run a slow, light, unbroken pass and then a second one than one heavy pass that stops twice. And check the pivot hasn’t crept out of its scrap before the second pass. If it has, the second pass cuts a second circle a hair away from the first, and now you have two edges and no good one.

Cleaning up the edge

A cut circle isn’t finished until the edge is round in section too.

Finished round leather coasters with burnished edges beside round drive punches and leather plugs.

The cut is only half the circle. The other half is the edge, which on veg-tan gets bevelled, sanded and burnished, the same as any other edge. Those steps are covered in the walkthroughs on beveling and creasing a strap and hand burnishing veg-tan edges. I hand-burnish edges for tradition, and on a circle the burnisher finds every flat spot the eye missed. Sand those down before the slicker goes on, or the burnish will polish the flaw.

Then the honest part, and it’s against myself. I cut briefcase parts with rulers and my eye, not templates, and there’s a separate piece on cutting a briefcase out of a bridle bend; my channel has a video of hand cutting a briefcase pattern. Work like a sculptor long enough and you start trusting your hands over any jig in the drawer. My opinion: a circle is the one shape where that pride loses. The eye can judge a straight edge and a square corner all day. It cannot hold a constant radius for a full turn, and nobody’s can. So use the template, the dividers, the cutter or the punch, and save the eye for checking the work, not making it. A coaster doesn’t care how proud the hands are.

WUTA Wing Divider: An adjustable stainless steel wing divider for marking a stitch line. See it on Amazon (affiliate link).

General Tools Scratch Awl with Hardwood Handle: A scratch awl with a hardwood handle. See it on Amazon (affiliate link).

Fiskars 18 x 24 Inch Self-Healing Cutting Mat: A self-healing cutting mat, 18 by 24 inches. See it on Amazon (affiliate link).

Farberware 12 x 18 Inch Reversible Plastic Cutting Board: A reversible plastic cutting board, 12 by 18 inches, usable as a cheap cutting surface under a knife. See it on Amazon (affiliate link).

OWDEN 9 Pieces Leather Hollow Punch Set: A nine-piece hollow punch set for round holes. See it on Amazon (affiliate link).

Leather Round Knife with Wooden Handle: A round knife with a wooden handle for cutting leather. See it on Amazon (affiliate link).

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