In this tutorial I’m going to show you how I used a blazer from a thrift store to make a blazer pattern. This is useful when you want to recreate a garment you already have, but you don’t want to destroy the garment in the process.
So here’s what we’re starting with. I found this size 4 blazer for $3.
To start with, I did the front piece.
I drew an L on the paper, lined up the side edge and bottom edge, traced the curve, and drew right through the button holes to mark them. Then I started adding pins to the side seam and the pocket.
You’ll notice that the top of this piece doesn’t lay flat. I started removing pins from the bottom, keeping a couple pins in place where the side seam met the armhole, and then would flatten and pin a little part, remove a few more pins, flatten and repeat. I also pinned the left edge to the line I drew to help stabilize the jacket as I flattened and pinned the seams.
Another problem you may run into happened to me at the point where the side seam met the underarm. During all my flattening and pinning of the armhole curve and shoulder seam, this spot got pinned several times. So what I ended up with looked like this:
As you can see, I didn’t use any of the precise pin marks to determine where my corner was, I went off the lines I was drawing and tried to keep my edges fairly straight.
OK, now on to seam allowances. This piece has a lot of curves, so I like to use a compass to help. Set it to the width of your seam allowance (in my case 1/2 inch)
Now use the pointy end to trace your existing line, while the pencil makes a new line that includes the seam allowance. Like this:
Now, here’s my finished pattern piece:
Trace the outside edges, the pin the seam, which should be easy since the collar should lie flat. Now you have this (ignore the uncut front pattern piece at the bottom of these pictures):
Now, we have to tidy this piece up since a collar is a symmetrical piece. If you just use the tracing as is, there will be slight variations between the right and left side. So, first measure from widest corner to corner, and then make a mark in the exact center above and below your ruler.
Use your compass to trace the edge of the cut piece, adding seam allowances.
Now cut out just the newly traced piece, and make sure to place on the fold when you pin it to your fabric.
OK, on to the back of the blazer. This will lay pretty flat, except around the armhole, so it will work much like the shirt front did. Draw your L and line up the bottom edge with it. Fold the fabric back to lay the side seam against the vertical line and pin in place.
Now, it would be tempting to assume that the side and center back seams are completely parallel and perpendicular to your bottom line, and here’s where the pinstripes on this blazer tell a different story. Look at the close up:
As you can see by the converging lines, the center back seam gets wider toward the top of the jacket. So go ahead and pin it out instead of just doing beginning and end points and connecting them with your ruler later.
Smooth and flatten in stages, just like you did on the front, trying to keep some pins in the center back seam to avoid pulling the jacket completely out of whack.
Now for the sleeves. Looking at this sleeve, I can see it is made of two parts, an upper and under sleeve. The red lines in the picture below are just outside the seam lines:
We’re going to start with the under sleeve, as it’s the easier. Simply line up the hem with your horizontal line, fold back to line up one side with your vertical line (I did this on the left, that’s why there are fewer pins on that side), and pin all around.
Now for the upper sleeve. This is tricky, as you can’t lay the whole sleeve flat at one time since it wraps around. Start with the L and line up the hem and the left edge. Pin around the armhole side, and trace the folded under edge.
Now, add some pins to keep the sleeve pinned shut. You’re about to flip the sleeve to trace the part that’s folded under, and you don’t want the fabric to shift on you when you do this.
Ok, now flip the whole jacket over, and line up what used to be the right side of your sleeve, and is now your left, with the vertical line you traced. You’ll probably notice the top won’t match up exactly because of the curve of the sleeve. That’s OK, get as close as you can and we’ll deal with the gap later. Pin what is now the seam on the right.
Close up of the armhole:
Now for the final piece! You need to have a piece for the facing on the front of the jacket, since the lapels will fold out and you want the fabric to match. The easy cheater way? Line it up with your already drawn front piece, and just pin the inside edge of the facing.