You're almost ready to cut into your quilt coat, but first, there's some pattern prep that needs to be addressed. We'll be going over how to take you're measurements, choose a size, and make basic fit modifications so that you end up with a coat you love. Here we go!
Contents
Taking your measurements
Don't skip this step or guess. If you haven't already purchased one, you'll need to a flexible tape measure like this.
Wearing your typical undergarments and standing comfortably (don't suck in your spare tire!), measure the following locations:
Bust - the circumference of the fullest part of your chest
Waist - the circumference at the smallest part of your torso
Hip - the circumference around the widest part of your pelvis
Other measurements you may want to take:
Upper chest - the circumference of your chest right under your armpits
Hem - the distance from your mid-shoulder to wherever you want the hem of your coat to sit
Arm length - from end of your collar bone to wherever you want the hem of the sleeve to sit when your arm is held straight out.
These measurements may or may not be listed on your pattern since they're more used for preference-type modifications.
You only really need to take these measurements once unless you happen to gain or lose a bunch of weight. Once you've taken them, write them down and keep them handy because we'll use them to decide on the base size for our coat pattern as well as make any basic modifications needed.
Choosing a base size
Every pattern has a size chart. Using the measurements you just established for yourself, choose the size that matches your measurements as close as possible. If you're between sizes, pick the one that most closely matches your bust size; that's the most important.
This will be your base size and it's what you should cut out most* of your pattern pieces at and then make modifications from there.
*If you're tapering between sizes (see below), you'll want to cut out your pieces at the larger of the two sizes.
When I took my measurements, here's what I got:
Matching that up to my patten dimensions, I find that I need to cut a straight large.
Basic Pattern Modifications
If the straight sizes in your pattern don't perfectly fit your dimensions (and let's face it, they almost never do), there are some easy basic modifications you can make to get a perfect fit.
Tapering between sizes
You may find that your bust is one size while your waist/hip is another. In this case, you can just taper the pattern pieces between these two sizes to mix sizes (shown by the yellow line in the image below).
These are really the only 2 measurements you should do that for though. You should never mix sizes between the bust and sleeve sizes. Those have to match.
Arm shortening/lengthening
Most patterns will come with a cut line or a lengthening line. On sleeve pieces, this will be somewhere around the elbow. This is where you will cut to either add or remove length.
To make an adjustment, determine how much length to add or remove by comparing your arm length measurements to the pattern's length measurements (if available) and adding or subtracting the difference from the pattern pieces.. If your pattern doesn't list length measurements for the finished garment (most don't), just measure that sleeve length of the pattern piece and subtract the seam allowance. That will get you pretty close.
The cavate is patterns where the sleeve seam is on the outer edge of the shoulder rather than in the standard, mid shoulder placement. If your coat pattern is in that category, you will need to remeasure your arm from where that sleeve seam will sit in the final garment. Use the pattern images to guestimate where this is. It doesn't have to be exact.
Cut the pattern piece along the lengthening line. If you need to add more length, use a ruler to draw a straight horizontal line on a fresh sheet of paper. Tape one piece down on that line and then measure the distance you need to add with a ruler drawing another parallel line. Tape the opposing half of the pattern at the newly marked line and then connect the pattern outline by sketching a gradual curve between the two and cutting around the new outline.
If you need to remove length, just divide the distance you need to remove by two and then remove that much from each half of the pattern piece my using a ruler to measure a straight line up from the cut edge. Tape the two pieces back together and then smooth out the outline to get a gentle curve.
Hem lengthening/shortening
Hem lengthening and shortening works the exact same way as arm shortening/lengthening. However, on a coat pattern, you'll need to make sure that you lengthening/shorten the back and front pattern pieces by exactly the same amount. Otherwise, when you go to sew the coat together, things won't line up.
Other modifications
Some other modifications include a full bust adjustment, for when your upper bust and bust measurements are different by more than ~2", and a small bust adjustment, for when your upper bust and bust measurements are less than 0.5" different. Both of these adjustments aren't difficult, but they're a little too involved to explain here. Check out this video for a good explanation, but unless your coat is particularly fitted, you probably don't need to worry about this adjustment. Some patterns also helpfully come with additional templates for different cup sizes. These are just pattern pieces with the full/small bust adjustments already made for you. Just choose your bra cup size.
We'll also get into adding buttons, zippers, pockets, etc. later, but if you plan on having buttons that close by overlapping the piece underneath (rather than toggle buttons), you'll want to make sure you extend the closure side of the front bodice piece, from hem to neckline, by about 1 1/2". This is only if your pattern doesn't already include instructions for buttons.