Are you struggling to get smooth curves and precise angles in your pattern making?
A lot of the time, it comes down to having the right rulers. These are the pattern drafting rulers I use when I hand draft, what each one is for, and which ones I’d buy first if I were starting over.
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The short version
→ Clear 18″ ruler: the one I use most. Seam allowance, grainlines, and even measuring curves.
→ Hip curve: side seams and waistlines on skirts and pants.
→ Armhole curve: armholes and necklines.
→ French curves: you don’t need the whole set. Two shapes cover almost everything.
→ L square: right angles on long drafts like pants and long skirts, plus marking hems.
→ Flexible ruler: for curves too tight for your clear ruler.
→ Long metal ruler: at least a yard long, for long straight lines and wide fabric.
→ Quilting rulers: cutting bias, squaring, and waistbands.
What are pattern drafting rulers?
Pattern drafting rulers are specialized tools that help you draft, alter, and perfect garment patterns with precision.
We all come in different shapes and sizes, with our own curves. To make garments that really fit, you need tools that can recreate those curves: the hip, the armhole, the neckline. That’s what these rulers do.
The clear 18″ ruler
This is a staple in any pattern maker’s toolkit, and it’s the one I reach for the most. Because it’s clear, you can see the paper or fabric underneath, so your placement is precise. Here’s the clear ruler I use.
I use it three main ways:
1. Adding seam allowance. I usually print my patterns with just the stitch lines. I trace the stitch line with a tracing wheel, then line the 5/8″ mark on the ruler up with that line and trace again. Now I have my seam allowance. You can even walk it around a curve with both hands. It takes some practice, but it works.
2. Lining up grainlines. Line the ruler up with the grain of the fabric. I measure 4″ from the edge at one end of the grainline, pin it, then move to the other end and adjust until it hits 4″ there too. Now the pattern is on grain, and you can smooth out and pin the rest. (Remember your tracing paper goes between the fabric and the pattern.)
3. Measuring curves. This ruler bends, so you can walk it around a curve like a sleeve cap to measure it and mark notches, then compare it to your armhole. Be careful, though. They can break if you bend them too far or too often, and mine have.
Keep it away from your iron. It will warp if it gets too hot, especially when you’re working on hems.
The hip curve
A hip curve is ideal for drafting the curved lines on skirts, pants, and hip seams. Its shape follows the natural curve of the body, so it’s much easier to draft garments that fit well.
I use it to draw the side seam from the widest part of the hip up to the waist, and to shape the waistline, which usually needs a slight curve.
Here’s a tip for the waistline: close your darts first by pinching and folding the pattern paper, then draw one smooth curve across the whole waist. When you open it back up, all of your dart legs will be even.
Some hip curves come built into other rulers. The Dritz Styleline ruler has a hip curve, an armhole curve, and a 16″ clear ruler all in one. I use mine so much that it’s broken a few times!
The armhole curve
An armhole curve is designed specifically for the shape of the armhole. The markings tell you which section to use. On my Dritz Styleline, for example, the armhole section is marked 13 to 26. When you’re drafting a sloper, you pivot the ruler along the line to get the curve exactly how you want it.
It’s also super handy for necklines, both the front neckline and the center back neckline.
French curves
French curves are made for smooth, flowing curves: necklines, armholes, and any curved seam.
You can buy them in a whole set, but honestly, you don’t need all of them. I use two shapes about 99% of the time. I call them the sleigh and the swoop. (I’m not sure those are their real names, but that’s what I’ve always called them!)
→ The sleigh has both an inside and an outside curve. It’s great for smaller armholes, like children’s sizes or half-scale patterns, and for sleeve caps.
→ The swoop is my go-to for center back necklines.
They’re especially helpful after draping. When you have a slight curve to work from, they help you turn it into a clean, crisp line.
If you’re only buying one or two, get those two shapes instead of a full set.
The L square
An L square is made for drafting right angles.
I don’t use it much for basic bodices or sleeves, because I can get better right angles with my clear ruler. But when I’m drafting pants or long skirts, I need a perfectly square line over a long length, and that’s when it really shines.
I also use it to mark hems. Stand the short side on the floor, measure up, and pin all the way around.
The flexible ruler
A flexible ruler bends to match any curve you need to measure. I don’t use it as often as my clear ruler, but it’s great for curves that are too sharp for the clear ruler and for marking notches. It’s a good tool to have.
A long metal ruler
I highly recommend a long, 2″ wide metal ruler. Mine is 48″ long.
When you’re drafting pants and skirts, you can draw one long, perfectly straight line instead of piecing it together in 18″ segments. I recommend one that’s at least a yard long. That also lets you measure fabric, and reach the center of a wide piece of fabric to line up a grainline when an 18″ ruler won’t get there.
Quilting rulers
I use quilting rulers a lot, especially for cutting bias strips or anything I’m cutting on a rotary mat. The hard plastic edge is great for that, and the angles are already printed on them.
They’re also really handy for drafting waistbands or anything that needs to be square, because they’re already square.
How to take care of your rulers
→ Keep them clean. Bits of debris under the ruler will keep your lines from being flat and crisp.
→ Store them flat or hang them. This matters most for the clear, bendy ones.
→ Keep them away from heat. Plastic rulers warp near an iron.
→ Practice. The more you use them, the better you’ll get, and the more ways you’ll find to use them.
Quick answers to common questions
Start with a clear 18″ ruler, a hip curve, and an armhole or French curve. Add an L square and a long metal ruler when you start drafting pants and long skirts.
No. I use two shapes, which I call the sleigh and the swoop, about 99% of the time. Those two will cover most armholes, sleeve caps, and necklines.
Drafting the curved lines on skirts and pants: the side seam from the hip up to the waist, and the slight curve along the waistline.
Trace your stitch line, then line the 5/8″ mark on a clear ruler up with that line and trace again along the ruler’s edge.
Heat. Plastic rulers warp if they get too close to an iron. Store them flat or hanging, away from heat.
I’ve linked the ones I use throughout this post. You can also find them at sewing supply stores.
Ready to draft digitally too?
I love hand drafting, and I also teach digital pattern drafting in CLO3D, Illustrator, and Affinity Designer. If you’re curious about going digital, start with my free CLO3D beginner roadmap.
Happy patterning,
Christina
