Project 002: Drafting with Circles and Curves
In today's post, I'll show you how to draft circles and curves on paper and digitally. Plus, we'll take some body measurements to prepare for drafting a hat.
Today’s post is intended to prepare us to start drafting actual hats. To see the full schedule of posts, check out last week’s launch post here:
The #1 rule of drafting and sewing curves
Circles and curves can be trickier to handle than rectangles but it is worth conquering any fear you might have. The most important thing to remember when sewing or drafting with a curved line is:
CUTTING LINES DO NOT EQUAL SEAM LINES
Because of the nature of a curve, the length of the cut line and the length of the seam line are NOT equal. This is something that can really trip people up. Please remember, that any time we add seam allowance to a curve, that new cutting line will be a different length. So, if you are measuring a seam line, remember that the cut edge is not the same.
This is also a good reminder of why it’s so important to add a seam allowance to your pattern. If you forget, the pattern pieces will sadly not fit together.
With our last project, we were using rectangles, gathers and extra ease so if you forgot to add seam allowance, your garment would still sew together and probably still fit just fine. We’re going to need to pay extra attention to the seam allowance with our sunhats.
For a convex curve, the cutting line will be longer than the seam line. For a concave curve, it’s the opposite. If you’re having trouble visualizing why it works like this, I like to imagine drafting a circle. If we add a seam allowance to the outside of the circle, that new circle is bigger and the cutting line is longer. (We’ll do this when we draft the hat crown.)
For a concave curve (like the inside brim of the hat), we’ll be adding seam allowance to the inside of the circle. In that instance, the cutting line is smaller.
Taking Measurements for a Hat
There are just three measurements that you need to take to draft a custom hat. So grab your flexible measuring tape and maybe a friend to help. If you have a hat that you like the fit of, you can also measure that as a reference for the finished measurements (that is body measurement + ease).
Head Circumference This is the most important measurement and will help make sure that the hat fits just right around your head. If you have thick hair, you may want to account for that as well (i.e. don’t squish your hair down too much). Or, if you know you’ll want to tuck your hair up into your hat, account for that in the measurement.
Crown Depth This measurement will be used to draft the side pattern piece of the flat crown sunhat and the bucket hat. If you have a bucket hat that you like, you can also use that as a guide.
Ear to Ear We’ll use this measurement when drafting the rounded sunhat. Using the flexible measuring tape start at the top of one ear (where the bottom of the hat will sit) and measure over the head to the top of the other ear.
Drafting Circles and Curves
Most of the time when I'm drafting, I use Adobe Illustrator. It's quick to use, saves paper and it has built in tools that can measure a line and add seam allowance. Plus, I love that I can be really exact. But, I know that not everyone has access to Illustrator or an equivalent vector software program.
So, I'll show you how to draft digitally AND how to draft on physical paper. I made a video for both approaches, each about six minutes long. I’ve also typed out the advice/instructions but I think it’s helpful to actually see the drafting in action.
PAPER DRAFTING
Click here to watch the video on Vimeo
For paper drafting, you'll need paper, pencil/pen, scissors, a flexible measuring tape and straight rulers. For drafting circles, you can also use a compass. For curves, it's also nice to have a curved ruler.
To draw a circle, you’ll start by calculating the radius of the circle. I shared that formula in last week’s newsletter. You’ll solve for R=C/(2π). Then fold a piece of paper into quarters (by folding once lengthwise and once widthwise). The folded corner will be the center of the circle. Use a ruler to mark the distance of the radius from the center to create a quarter circle. Add a seam allowance and cut through all layers of the paper.
To make an oval, we will draw a curved line that equals 1/4 of the circumference. Divide the circumference by 4. Then draw or fold an X-Y axis through the center of a piece of paper. Use a flexible measuring tape or a curved ruler to draw 1/4 of the oval on the paper. (Make sure that the curves meet the X and Y axis at a 90 degree angle so that you’ll have a smooth line.) Add a seam allowance. Then fold the paper into fourths and cut out the oval.
To measure a curve drawn on paper, use the flexible measuring tape holding the edge of the tape perpendicular to the paper.
DIGITAL DRAFTING
Click here to watch the video on Vimeo.
My favorite way to draft patterns is in Adobe Illustrator. There are a lot of benefits to digital drafting. I can do it anywhere I have my laptop. It saves paper. And, I can create very exact shapes. (I also use it to grade patterns!)
In the video, I show the basics of drafting with circles and curves, including how to draw circles and ellipses, how to measure the circumference of an ellipse and the length of a curved line. Plus, I show how I adjust an ellipse or curved line to get exactly the length I want.
By the way, when you draw a circle in Illustrator, you will input the Diameter of the circle in the width and height. The Diameter equals the Circumference divided by π. D=C/π
The most helpful tools are the Ellipse Tool (keyboard shortcut “L”), the Transform palette and the Document Info palette. When using the Document Info palette, select “Object Info” from the triple bar (aka hamburger) button to see the length of the path selected.
I hope you found this exercise helpful. Let me know in the comments if you have any questions. Next week, we will dive into hat drafting by designing and drafting a stove pipe style hat.
Happy mathing!
Beth
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