{Capsule Wardrobe Sew Along} "Muslins aren't magic. They're math." And other Pre-Muslin Matters

Oh boy. How's THAT for a fun title? Muslin is a bit of a dirty word itself (until it saves your beautiful stash fabric from a simple mistake!) - but what the heck is a PRE-muslin?

Well. I kind of made it up. I don't know if it is a term, or if there's another term for it, but I'm rolling with "pre-muslin" - and here's what it means to me:

A pre-muslin is the set of adjustments made to a pattern BEFORE it is test-sewn. These include size-selection, size-blending, full or small bust adjustments, and length adjustments.
— me, my brain.

Half of you just died. CPR might make things weird, so here - let me fan you off until you come to.

Fist up: Research.

Before you know how a pattern will fit you, you need to know WHO it is designed to fit. Most designers will include some verbiage on their websites or in their patterns to give you this information. What size bust do they draft for? What height woman? This chart will save you some hunting for that information:

What do you notice? Well - for starters - most every designer on this list drafts for someone in the 5'5-5'6 range. This is "average" height.

They also draft for a B or C cup. There are a few designers who suggest they draft for a range of cup sizes. Either, their patterns have multiple cut lines for each cup size, OR they're relying on the forgiving fit of knit to provide that range. Not necessarily implying this is correct, or incorrect, just something you should know as you evaluate your pre-muslin fit adjustments.

Then: Compare your Measurements.

(Which I presume already you know how to take. If you don't - side step over to Judy's fully illustrated post for assistance!)

There are two sets of measurements you need to know. The first set covers length, the second covers width. Frustratingly, only one half of those measurements are made available within the pattern. Those are the width measurements: bust, waist, and hip circumference. 

Compare your measurements to the pattern's size chart. What size do I choose for my bust? What size do I choose for my waist? My hips? If you have an average size bust, and an hourglass body shape, you will most likely fit pretty comfortable in one size. (Lucky duck..) BUT...

  • If you have a D or larger bust, or a B or smaller bust, you will have to do a pre-muslin adjustment.
  • If you are any other body type, you will have to do a pre-muslin adjustment.
  • If you are +/- 1 inch off from the drafting height, you will have to do a pre-muslin adjustment.

BOOOOOOOOOO! I know, it sucks. Don't shoot the messenger! I just blog the rules, I didn't make them. Besides- I'm no where near exempt. My petite pear shape requires plenty of alterations. So where do we start?


Length Adjustments

ALWAYS FIX LENGTH BEFORE YOU FIX WIDTH. You need to line up the bust point with your bust, the waistline at your waist, and the hip at your hip. 

I happen to be 5'2 AND A HALF! I always used to joke that that half inch mattered. And, as it turns out with tailoring, it totally does.

I'm 2.5 inches shorter than the Colette Pattern's drafting height. In pattern drafting speak, that's the difference of FIVE sizes. See? PS: these charts are all available here.

You may be tempted (or misinformed) to say "So take some length off the hem, what's the big deal?" Well, that'd be great and all, if God had made my body just.. shorter at the bottom of the torso. But he knew that'd look really silly. So instead, he made my body proportionally smaller than the "average" 5'5 body. Way to look out, Big Guy

Pattern drafters know this - and this chart confirms it too. Look at how much smaller my measurements are versus the ones my pattern was built for:

For grins, let's imagine what it would look like if I made a pattern straight from the original pieces. 

  • The pattern's bust point would be about 1.5 inches too low for my bust point. It would make my boobs look bigger (YAY!).... in the saggy, "your clothes just aged you 20 years" kind of way. (Not yay...)
  • The pattern's waistline is 2 inches (1.5+0.5) lower than my waistline. That means my waist is now swimming in excess fabric, because the designer expects most women's rib-cages (wider than a waistline) to be there instead. Now I have saggy looking boobs AND a bulky waist. 
  • The pattern's waistline hits at my (broader) high hip. My hips need to fit somewhere - so they'll force the shirt upwards In search of more space in the garment (which it will find nearly 3 inches LOWER in the garment - 1.5+0.5+1). Where does that excess 3 inches of shirt fabric go?? MY WAISTLINE. Now I have a full blown "spare tire" of excess fabric. If I wanted to look 10 lbs heavier, I'd do it the fun way and feast on craft brews and salted caramel cupcakes. 

So here's my pre-muslin "diet". Lose 10 lbs before I even cut into my test fabric:

I find the midpoint between my shoulder and bust point, and remove the pattern's excess length. (About 1.5 inches!)

And I'll go in again and take out excess (0.5 inches) above the waistline, as well as another 1 inch to address the excess from my waist-to-hip measurement. (Total 1.5 inches off the waistline)

That. Seems. CRAZY. That's THREE FULL INCHES. But I gave it a go anyway.... Because measurements do not lie. We're halfway to our muslin, let's now address the...

Width Adjustments

I know from the guide above that Colette drafts for a C cup. Which I happen to be. (On a good day... in a good bra....shh, let a girl dream!)

So when my bust measurement places me at the size 0 - I know that's the size I need at my bust.

BUT - My waist (27) puts me at the size 4, and my hips (38) put me at a size 6. (Woo, pear shape!)

Thankfully, all I have to do here is grab my ruler and a marker and "blend" those sizes.

This will give me a good start. But width adjustments are not black and white the way bust point and waistline placements are. If those don't line up perfectly, the fit is WRONG. 

So why isn't that the case with width adjustments?? Because ultimately how wide a pattern is is a matter of preference. How tight do you want your clothes to fit? There is no universal answer. It changes in part by generation, it changes from designer to designer, and it changes from pattern-to-pattern. The calculation designers use to determine how wide a pattern will be is called "ease." In it's simplest form, "Ease" is the difference between your body's actual width measurements, and the garment's actual width measurements.

  • Woven garments need 2 or more extra inches of ease to account for movement.
  • Fitted woven garments may have less than an inch of ease. (That's what makes them "fitted"!)
  • Fitted knit garments often have NEGATIVE ease. That is, the fabric itself is expected to stretch to fit properly. 

So, at best, my size blending efforts here will show me how the DESIGNER wants the garment to fit me. I may agree, and my muslin may be perfect.

OR, I may want to take it in. Or out. Either way, this is why we don't skip our muslins! (And why we sew them with a generous seam allowance.)

Last Step! Bust Adjustments.

IF you know you're not a B-C cup (or whatever size cup your designer drafts for - reference the chart up at the top of this post) then you KNOW this muslin will not fit you well. You need more (or less) space for your bust, and there's no use sewing a muslin before your pattern pieces reflect that customization.

I am of course referring to FULL an SMALL BUST ADJUSTMENTS (FBA's and SBA's). And I've never done one before, because my body just doesn't need one (yet). But they are exceedingly common, and there are various resources to walk you through that adjustment on our Capsule Group's fitting board:


By now, you've FINALLY sewn up your muslin. (Oh, sorry, go do that now. I'll wait! Back? Fabulous! Let's continue...) HOW do you know if it fits you well?

  • Bust darts will point directly to your apex (the G rated seamstress alternative to "nipple"). The end of the dart will hit more or less an inch away from the apex.
  • There is no wrinkling, gaping, or puddling. Aka, excess fabric of any kind.
  • There is no pulling. Aka, a fabric deficit of any kind.

...That's really it! Good fit is really easy to see when you're looking for it. Sadly, in our "ready to wear" world, we've become completely desensitized to poor fit. We don't see it because we don't look for it. And now you will.


Of course, there are other pre-muslin adjustments many of you will need.. But beginners, expect it to take you a few muslins to learn your body's required set of alterations. 

And don't worry!! This process gets easier as you go. Why? Well, for starters you know the NAMES of all these adjustments. Fixing them is easy when you know what to Google. (For instance, the exceedingly common Sloping Shoulder, or Sway Back adjustments. They take just minutes to fix.. as soon as you can search for "how??")

But for now - (pre) Muslin by Numbers. You know your lengths, you know your widths, you know your bust size. That alone will fix 90% of fit issues. Now go forth and muslin with confidence, my friends! Muslins aren't magic. They're math.